Variable wheel moving apparatus

Abstract

This variable wheel moving apparatus comprises a main frame unit, a driving wheel unit, a sub-frame unit, and a link unit. The main frame unit includes a main frame main body and a main frame that branches and extends from the main frame main body. The driving wheel unit includes driving wheels connected to the ends of the main frame to be driven. The sub-frame unit includes a sub-frame main body and a sub-frame that branches and extends from the sub-frame main body. The link unit is rotatably connected between the driving wheels and the sub-frame. The link unit is rotated by the rotation of the sub-frame unit such that the radius of the central axis of the driving wheel unit is varied with respect to the central axis of the main frame unit.

Description

Variable wheel travel device

[0001] The present invention relates to a variable wheel moving device, and more particularly, to a variable wheel moving device in which the length of the wheel is variable to correspond to the height and width of the stairs, thereby enabling the device to climb stairs having various heights and widths.

[0002] Recently, various mobile vehicles have been used to load and transport cargo, fight fires, and rescue people.

[0003] These mobile robots include crawler robots, multi-legged walking robots, and tri-spoke robots that can be controlled remotely using joysticks or remote controls.

[0004] Here, the crawler robot is configured in a wheel / track type form to move while overcoming complex terrain features.

[0005] Multi-legged walking robots are structures suitable for overcoming complex terrain features and are designed to move by walking.

[0006] The wheel robot is equipped with three wheels radially, and the three wheels are driven to move and rotate while climbing stairs, etc.

[0007] Among these mobile devices, those with a wheel robot structure can only climb stairs below a set height.

[0008] That is, because the wheels are manufactured by setting the length and spacing between the wheels to correspond to the height of a typical staircase, climbing is possible for stairs below the set height, but climbing is difficult for stairs exceeding the set height.

[0009] Additionally, there is a problem that it is difficult to climb if the width of the stairs is narrower than the set width.

[0010] Accordingly, there is a need for a mobile device that can overcome the limitation of the height and width of stairs that a mobile device with a wheel structure can climb, and can climb regardless of the width and height of stairs.

[0011] Related prior art literature includes Republic of Korea Patent No. 10-0534465.

[0012] Based on the technical background described above, the present invention provides a variable wheel moving device that has a plurality of wheels arranged radially at equal angles to enable free movement while maintaining efficient and stable driving performance on flat ground, can easily climb stairs with power provided through a power supply unit, and can be transformed and varied into an optimized form for stairs of various heights and widths by making the length from the central axis to the wheels variable in accordance with the height and width of the stairs, thereby enabling stable climbing of stairs.

[0013] According to one embodiment of the present invention, a variable wheel moving device includes a main frame portion, a driving wheel portion, a sub-frame portion, and a link portion. The main frame portion includes a main frame body and a main frame branching and extending from the main frame body. The driving wheel portion includes a driving wheel drivably connected to an end of the main frame. The sub-frame portion includes a sub-frame body and a sub-frame branching and extending from the sub-frame body. The link portion is rotatably connected between the driving wheel and the sub-frame. The link portion rotates by the rotation of the sub-frame portion, thereby varying the radius of the central axis of the driving wheel portion with respect to the central axis of the main frame portion.

[0014] In one embodiment, the main frame may be formed by branching in N directions (N is a natural number) from the center of the main body of the main frame, and the sub-frames may be formed by branching in N directions from the center of the sub-frame main body.

[0015] In one embodiment, the power supply unit may further include a gear unit interposed between the driving wheel unit and the main frame to transmit power, a first power supply unit that transmits power to the driving wheel unit, a second power supply unit that transmits power to the main frame unit, and a third power supply unit that transmits power to the subframe unit.

[0016] In one embodiment, the link portion may include first and second links provided on each side of the gear portion and rotating the gear portion in conjunction with the subframe portion.

[0017] In one embodiment, the first link may extend in one direction and have a plurality of first through holes formed therein, and the second link may extend in one direction, including a step portion, and have a plurality of second through holes formed therein.

[0018] In one embodiment, the step portion may include a first step portion formed on one side of the second link and to which the gear portion is connected, and a second step portion formed with a thickness smaller than the first step portion and to which the subframe is connected.

[0019] In one embodiment, the pin section may further include at least one fixed pin connecting the link section, the gear section, and the sub-frame section, and a wheel moving pin movably connecting the main frame section, the gear section, the link section, the sub-frame section, and the driving wheel section.

[0020] In one embodiment, the main frame portion may include a first coupling portion protruding from the center of the main frame body and to which the first power supply portion is coupled, and a slot portion formed along the extension direction of the main frame at an end of each main frame and through which the wheel movement pin moves.

[0021] In one embodiment, the first coupling portion may be formed with a second coupling hole to which the second power supply portion is coupled.

[0022] In one embodiment, the driving wheel includes a wheel body, a wheel axle connected to the wheel body, and a wheel engaging groove formed on the wheel axle to which the wheel moving pin is engaged, and the position of the driving wheel can be changed with respect to the central axis of the main frame portion according to movement of the wheel moving pin.

[0023] In one embodiment, the second power supply unit can rotate the main frame unit, and the third power supply unit can rotate the sub-frame unit.

[0024] In one embodiment, the gear unit may include a main gear rotatably connected to the first power supply unit, and a plurality of driven gears that are continuously gear-coupled to one another in one direction from the main gear and rotate in conjunction with the main gear.

[0025] In one embodiment, the driving gear rotates by power provided from the first power supply unit, and the driven gears rotate sequentially according to the rotation of the driving gear, so that a driving wheel connected to the driven gear can be driven.

[0026] In one embodiment, as the subframe portion rotates by power provided from the third power supply portion, the driven gears may change position, so that the distance from the driving wheel to the central axis of the main frame portion may change.

[0027] In one embodiment, the driven gears include first to third driven gears, the first driven gear being gear-coupled to the main gear and connected to the link portion and the subframe portion, the second driven gear being gear-coupled to the first driven gear and connected to the link portion, and the third driven gear being gear-coupled to the second driven gear and connected to the main frame portion, the link portion, and the drive wheel portion.

[0028] In one embodiment, the first driven gear may be connected to the link portion and the sub-frame portion with the fixed pin, the second driven gear may be connected to the link portion with the fixed pin, and the third driven gear may be connected to the main frame portion, the link portion, and the driving wheel portion with the wheel moving pin.

[0029] In one embodiment, the subframe body is coupled to the main gear and the third power supply, and the subframe can be coupled to the driven gear.

[0030] In one embodiment, the subframe body and the main gear may be coupled by a second coupling portion formed on one side of the subframe body, and the subframe body and the third power supply unit may be coupled by a third coupling portion formed on the other side of the subframe body.

[0031] In one embodiment, the power transmission unit may further include a power transmission unit that transmits power from the first power supply unit to the main gear.

[0032] In one embodiment, the power transmission unit may include a transmission body, a connection groove formed on one side of the transmission body to which the first power supply unit is connected, and a fourth coupling unit formed on the other side of the transmission body to which the first power supply unit is connected.

[0033]

[0034] As described above, according to the present invention, a plurality of wheels are arranged radially and equiangularly, so that free movement is possible while maintaining efficient and stable driving performance on flat ground, and stairs can be easily climbed with power provided through a power supply unit, and the length from the central axis to the wheels is made variable to correspond to the height and width of the stairs, so that it can be transformed and varied into an optimized shape for stairs of various heights and widths, thereby having the effect of climbing stairs stably and smoothly.

[0035] FIG. 1 is a front perspective view showing a variable wheel movement device according to a first embodiment of the present invention.

[0036] Fig. 2 is a rear perspective view showing the variable wheel movement device of Fig. 1.

[0037] Fig. 3 is an exploded perspective view showing the variable wheel movement device of Fig. 1.

[0038] Fig. 4 is a drawing showing a driving mode in which the variable wheel travel device of Fig. 1 operates.

[0039] FIGS. 5A to 5C are drawings showing a climbing mode in which the variable wheel moving device of FIG. 1 moves while climbing stairs.

[0040] FIG. 6a and FIG. 6b are drawings showing a variable mode in which the length of the variable wheel travel device of FIG. 1 is variable.

[0041] FIG. 7 is a rear perspective view showing a variable wheel movement device according to a second embodiment of the present invention.

[0042] FIG. 8 is a drawing showing a variable wheel movement device according to a third embodiment of the present invention.

[0043] <Explanation of symbols>

[0044] 1a, 1b, 1c: Variable wheel travel device

[0045] 10: Main frame section 11: Main frame body

[0046] 11a: Axle hole 13: Main frame

[0047] 13a: First main frame 13b: Second main frame

[0048] 13c: Third main frame 15: First joint

[0049] 15a: First coupling hole 15b: Second coupling hole

[0050] 17a, 17b, 17c: Slot section 20: Drive wheel section

[0051] 20a: First drive wheel 20b: Second drive wheel

[0052] 20c: Third drive wheel 21: Wheel body

[0053] 23: Wheel axle 25: Wheel connecting groove

[0054] 30a, 30b: Gear section 31, 31': Main gear

[0055] 32a: Main gear body 32b: Screw part

[0056] 32c: 1st hollow 33, 33': Driven gear

[0057] 33a: 1st driven gear 33b: 2nd driven gear

[0058] 33c: Third driven gear 34a: Driven gear body

[0059] 34b: Screw part 34c: Second hollow part

[0060] 36: Drive gear 38: Connecting member

[0061] 40: Subframe section 41: Subframe body

[0062] 43: Subframe 43a: First subframe

[0063] 43b: 2nd subframe 43c: 3rd subframe

[0064] 45a, 45b, 45c: Spoke hole 46: Second joint

[0065] 47: Third joint 47a: Joint groove

[0066] 50: Link section 51a, 51b, 51c: First link

[0067] 52: 1st link hole 53a, 53b, 53c: 2nd link

[0068] 54: Step section 54a: First step section

[0069] 54b: Second step 55: Second link hole

[0070] 60: Power supply unit 60a: First power supply unit

[0071] 60b: Second power supply unit 60c: Third power supply unit

[0072] 61a: First power coupling 61b: Second power coupling

[0073] 61c: Third power coupling 70: Fin section

[0074] 71: Wheel shift pin 73: Stopper

[0075] 75: Fixed pin 80: Power transmission unit

[0076] 81: Transmission body 81a: Connection home

[0077] 83: Flange section 85: 4th joint section

[0078] 91: Connecting ring 91a: Connecting hole

[0079] 95: Sensor section

[0080] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0081] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In the present invention, it should be understood that the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0082] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Please note that, where possible, identical components are represented by identical reference numerals throughout the drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted.

[0083] Fig. 1 is a front perspective view showing a variable wheel travel device according to a first embodiment of the present invention. Fig. 2 is a rear perspective view showing the variable wheel travel device of Fig. 1. Fig. 3 is an exploded perspective view showing the variable wheel travel device of Fig. 1.

[0084] Referring to FIGS. 1 to 3, a variable wheel moving device (1a) according to a first embodiment of the present invention includes a main frame part (10) including a main frame body (11) and a plurality of main frames (13) branched and formed on the main frame body (11), a driving wheel part (20) including driving wheels (20a, 20b, 20c) each connected to an end of each main frame (13), a gear part (30a) interposed between the driving wheel part (20) and the main frame part (10) to transmit power, a sub-frame part (40) including a sub-frame body (41) and a plurality of sub-frames (43) branched and formed on the sub-frame body (41), a link part (50) including a plurality of first links (51a, 51b, 51c) and second links (53a, 53b, 53c) that rotate the gear part (30a) in conjunction with the sub-frame part (40), a first power It may include a power supply unit (60) consisting of a supply unit (60a), a second power supply unit (60b), and a third power supply unit (60c).

[0085] In addition, the variable wheel moving device (1a) according to the present embodiment may further include a pin portion (70) composed of a fixed pin (75) connecting the link portion (50), the gear portion (30a), and the sub-frame portion (40), and a wheel moving pin (71) connecting the main frame portion (10), the gear portion (30a), the link portion (50), the sub-frame portion (40), and the driving wheel portion (20).

[0086] Specifically, the main frame section (10) may include a main frame body (11) and three main frames (13) each having a predetermined length and branching in three directions based on the center of the main frame body (11), but arranged equiangularly. Through the drawing, it is exemplified that the main frame section (10) is formed by branching in three directions from the center of the main frame body (11), but it is not necessarily limited to three directions and may be formed by branching in N directions (N is a natural number). However, for the convenience of explanation, the following description will exemplify branching in three directions equiangularly, and in the case of other structures branching in N directions, it is sufficient if only the number of branches is different and formed substantially the same as the contents described below.

[0087] Here, the main frame (13) may include a first main frame (13a), a second main frame (13b), and a third main frame (13c) that are formed to extend from the main frame body (11).

[0088] An axis hole (11a) can be formed through the central axis of the main frame body (11).

[0089] A first coupling part (15) having a first coupling hole (15a) formed in the center of the other side of the main frame body (11) to allow the first power supply part (60a) to be coupled can be protruded.

[0090] At this time, the shaft hole (11a) and the first coupling hole (15a) can be connected to each other.

[0091] At the end of each main frame (13a, 13b, 13c), a slot portion (17a, 17b, 17c) may be formed long enough to allow a wheel movement pin (71) to be movably connected in the longitudinal direction of the main frame (13a, 13b, 13c).

[0092] Here, the spacing and distance between the central axis of each driving wheel (20a, 20b, 20c) and the central axis of the main frame portion (10) can be set according to the length of each slot portion (17a, 17b, 17c).

[0093] Accordingly, the length of the slot portions (17a, 17b, 17c) can be varied in various ways depending on the height and width of various types of stairs, but is not limited thereto.

[0094] Meanwhile, a second coupling hole (15b) may be formed through the outer circumference of the first coupling portion (15) to allow the second power supply portion (60b) to be coupled thereto.

[0095] The driving wheel part (20) is provided on one side of the main frame part (10), and can be rotatably connected to a slot part (17a, 17b, 17c) formed at the end of each main frame (13) by a wheel moving pin (75).

[0096] For this purpose, the driving wheel unit (20) may include a first driving wheel (20a) connected to the first main frame (13a), a second driving wheel (20b) connected to the second main frame (13b), and a third driving wheel (20c) connected to the third main frame (13c).

[0097] Accordingly, each driving wheel (20a, 20b, 20c) can also be arranged in three directions based on the center of the main frame body (11) to correspond to each main frame (13a, 13b, 13c).

[0098] Each driving wheel (20a, 20b, 20c) may include a wheel body (21) formed in a cylindrical shape to enable driving and climbing on the ground and stairs, a wheel axle (23) protruding from the center of the side of the wheel body (21), and a wheel coupling groove (25) formed at the center of the wheel axle (23) and into which a wheel movement pin (71) is inserted and coupled.

[0099] Here, it is also possible to improve the ground contact and ground force between each driving wheel (20a, 20b, 20c) and the ground and steps by forming protruding portions (not shown) in the shape of embossments at regular intervals in the outer periphery of the wheel body (21), but the present invention is not limited thereto.

[0100] The gear part (30a) can be interposed between the driving wheel part (20) and the main frame part (10) to transmit power.

[0101] Specifically, the gear unit (30a) can transmit power provided from the first power supply unit (60a) to each driving wheel (20a, 20b, 20c) of the driving wheel unit (20) to rotate each driving wheel (20a, 20b, 20c).

[0102] The gear unit (30a) can rotate by power provided from the third power supply unit (60c) to change the position of each driving wheel (20a, 20b, 20c).

[0103] For this purpose, the gear unit (30a) may include a main gear (31) and a plurality of driven gears (33) that are meshed with, or gear-coupled to, the main gear (31) and rotate in conjunction with the main gear (31).

[0104] The plurality of driven gears (33) may include a first driven gear (33a) that is engaged with the main gear (31), a second driven gear (33b) that is engaged with the first driven gear (33a), and a third driven gear (33c) that is engaged with the second driven gear (33b).

[0105] The main gear (31) is a cylindrical body and may include a main gear body (32a) having a first hollow (32c) formed in the center thereof and a screw portion (32b) in the shape of teeth that protrudes in the circumferential direction on one outer periphery of the main gear body (32a).

[0106] The driven gear (33) is a cylindrical body and may include a driven gear body (34a) having a second hollow (34c) formed in the center thereof and a screw portion (34b) in the form of teeth that protrude in the circumferential direction on one outer periphery of the driven gear body (34a).

[0107] Accordingly, the screw portion (32b) of the main gear (31) and the screw portion (34b) of the driven gear (33) are meshed with each other so that when the main gear (31) rotates, the driven gear (33) can rotate in conjunction with the main gear (31).

[0108] In addition, the screw portions (34b) of each driven gear (33a, 33b, 33c) are meshed with each other so that each driven gear (33a, 33b, 33c) can rotate in conjunction when the main gear (31) rotates.

[0109] That is, when the main gear (31) rotates, each first driven gear (33a) meshed with the main gear (31) rotates, when the first driven gear (33a) rotates, each second driven gear (33b) meshed with the first driven gear (33a) rotates, and when the second driven gear (33b) rotates, each third driven gear (33c) meshed with the second driven gear (33b) can rotate.

[0110] Here, the third driven gear (33c) which is positioned furthest from the main gear (31) among the plurality of driven gears (33) can be connected to each driving wheel (20a, 20b, 20c) by a wheel moving pin (75).

[0111] Accordingly, when the main gear (31) rotates, each first driven gear (33a) meshed with the main gear (31) rotates, and when the first driven gear (33a) rotates, each second driven gear (33b) meshed with each first driven gear (33a) rotates, and when the second driven gear (33b) rotates, each third driven gear (33c) meshed with each second driven gear (33b) rotates, so that each driving wheel (20a, 20b, 20c) connected to each third driven gear (33c) can be rotated.

[0112] Meanwhile, the main gear (31) is connected to the first power supply unit (60a) through the power transmission unit (80) described later, and can rotate with the power of the first power supply unit (60a) transmitted through the power transmission unit (80).

[0113] The sub-frame part (40) is connected to the gear part (30a), and may include a sub-frame body (41) and a plurality of sub-frames (43) having a predetermined length and branched in three directions based on the center of the sub-frame body (41), but arranged at equal angles.

[0114] At this time, in the case of the above sub-frame (43), it is exemplified that it branches in three directions, but as in the main frame described above, it can branch in N directions (N is a natural number). However, the number and direction of branches of the main frame and the sub-frame must be the same.

[0115] At this time, the sub-frame part (40) can have its central axis formed on the same axis as the main frame part (10).

[0116] Here, the plurality of sub-frames (43) may include a first sub-frame (43a), a second sub-frame (43b), and a third sub-frame (43c) that are formed to extend from the sub-frame body (41).

[0117] The sub-frame body (41) of the sub-frame section (40) and each sub-frame (43a, 43b, 43c) branched from the sub-frame body (41) are formed in a shape corresponding to the main frame body (11) of the main frame section (10) and each main frame (13) branched from the main frame body (11), but the sub-frame section (40) can be formed in a size smaller than the main frame section (10) as a whole.

[0118] A second coupling portion (46) may be protruded and formed on one side of the subframe body (41) toward the gear portion (30a) to be coupled to the main gear (31) of the gear portion (30a).

[0119] The second coupling portion (46) can be formed with a diameter corresponding to the first hollow (32c) formed in the main gear (31).

[0120] Here, the second coupling portion (46) can be inserted and coupled only to a predetermined depth into the first hollow (32c) of the main gear (31). That is, the second coupling portion (46) can be inserted and coupled only into the first hollow (32c) of the portion where the screw portion (32b) is formed in the main gear (31).

[0121] A third connecting portion (47) for connecting a third power supply portion (60c) may be protruded and formed at the center of the other side of the subframe body (41).

[0122] A coupling groove (47a) may be formed in the third coupling portion (47) to which the third power supply portion (60c) is coupled.

[0123] A spoke hole (45a, 45b, 45c) may be formed through the end of each subframe (43a, 43b, 43c) to be coupled with the first driven gear (33a) and the fixed pin (75).

[0124] Accordingly, the subframe body (41) can be connected to the main gear (31) through the second connecting portion (46), and each subframe (43a, 43b, 43c) can be connected to the first driven gear (33a) that engages with the main gear (31) through a spoke hole (45a, 45b, 45c) by a fixing pin (75).

[0125] The link portion (50) is provided on each side of the gear portion (30a), integrally connects the driven gear (33) of the gear portion (30a), and can rotate the gear portion (30a) by linking with the small tri spoke (40).

[0126] Specifically, the link portion (50) may include at least one first link (51a, 51b, 51c) provided between the gear portion (30a) and the main frame portion (10), and at least one second link (53a, 53b, 53c) interposed between the gear portion (30a) and the driving wheel portion (20) and connected to a small tri spoke (40).

[0127] Specifically, each first link (51a, 51b, 51c) is a bar-shaped plate, and a plurality of first link holes (52) can be formed at regular intervals in the longitudinal direction of the first link (51a, 51b, 51c).

[0128] In this embodiment, three first link holes (52) are formed to penetrate the first links (51a, 51b, 51c), but the number of first link holes (52) is not limited to this and can be changed.

[0129] Each second link (53a, 53b, 53c) is in the shape of a rectangular parallelepiped, and a step-shaped step (54) may be formed on one side facing the gear section (30a) and the subframe section (40).

[0130] Here, the step portion (54) may include a first step portion (54a) and a second step portion (54b), and the first step portion (54a) may be formed with a greater thickness than the second step portion (54b).

[0131] Each first step portion (54a) is connected to and in contact with one side of the second driven gear (33b) and third driven gear (33c) of the gear portion (30a) where the screw portion (34b) is formed, and each second step portion (54b) can be connected to and in contact with each sub-frame (43a, 43b, 43c) of the sub-frame body (41).

[0132] In the first step portion (54a), two second link holes (55) can be formed through the second hollow portion (34c) of the second driven gear (33b) and the third driven gear (33c), and in the second step portion (54b), one second link hole (55) can be formed through the second link hole (55) to correspond to the spoke holes (45a, 45b, 45c) of each subframe (43a, 43b, 43c).

[0133] Here, the second link hole (55) formed in the second link (53a, 53b, 53c) and the first link hole (52) formed in the first link (51a, 51b, 51c) can be arranged on the same axis.

[0134] Accordingly, the first driven gear (33a) can be connected to the second link hole (55) formed penetrating the second step portion (54b) of the second link (53a, 53b, 53c) and the first link hole (52) of the first link (51a, 51b, 51c) which is arranged to correspond to the second hollow portion (34c) of the first driven gear (33a) by a fixing pin (75).

[0135] At this time, spoke holes (45a, 45b, 45c) of each subframe (43a, 43b, 43c) may be arranged between the second step portion (54b) and the first driven gear (33a).

[0136] In addition, the second driven gear (33b) can be connected to a second link hole (55) formed to penetrate the first step portion (54a) of the second link (53a, 53b, 53c) and arranged to correspond to the second hollow (34c) of the second driven gear (33b) and a first link hole (52) formed to correspond to the second hollow (34c) of the second driven gear (33b) among the first link holes (52) of the first link (51a, 51b, 51c) by a fixing pin (75).

[0137] Meanwhile, the third driven gear (33c) can be connected to the second link hole (55) formed to penetrate the first step portion (54a) of the second link (53a, 53b, 53c) and the second hollow (34c) of the third driven gear (33c) and the first link hole (52) formed to correspond to the second hollow (34c) of the third driven gear (33c) among the first link holes (52) of the first tri-spoke by a wheel moving pin (71).

[0138] The power supply unit (60) is for transmitting power to the main frame unit (10), the driving wheel unit (20), and the sub-frame unit (40), and may include a first power supply unit (60a) coupled to the driving wheel unit (20) through a first power coupling unit (61a), a second power supply unit (60b) coupled to the main frame unit (10) through a second power coupling unit (61b), and a third power supply unit (60c) coupled to the sub-frame unit (40) through a third power coupling unit (61c).

[0139] A first power coupling portion (61a) may be formed protrudingly at one center of the first power supply portion (60a) to be connected to the gear portion (30a) via the main frame portion (10).

[0140] The first power supply unit (60a) can transmit power to the driving wheel unit (20) to drive the variable wheel moving device (1a).

[0141] Specifically, the first power coupling unit (61a) of the first power supply unit (60a) can be connected to the gear unit (30a) via the power transmission unit (80).

[0142] To this end, the power transmission unit (80) may be formed with a transmission body (81) formed in a cylindrical shape and a connecting groove (81a) formed in the center of one side of the transmission body (81) facing the main frame unit (10).

[0143] The first power coupling portion (61a) can be formed to correspond to the diameter of the connecting groove (81a).

[0144] In addition, the power transmission unit (80) may have a flange portion (83) formed at the other end facing the gear portion (30a), and a fourth coupling portion (85) may be formed protrudingly at the center of the flange portion (83).

[0145] The fourth connecting portion (85) corresponds to the diameter of the first hollow (32c) formed penetrating the main gear (31) of the gear portion (30a), and can be formed to protrude with a length shorter than the length of the first hollow (32c).

[0146] Accordingly, the fourth coupling part (85) can be inserted and coupled only to a predetermined depth into the first hollow (32c) of the main gear (31).

[0147] Due to this, the fourth coupling part (85) of the power transmission part (80) can be inserted and coupled from one side of the main gear (31) to the center of the first hollow (32c), and the second coupling part (46) of the sub-frame part (40) can be inserted and coupled from the other side of the main gear (31) to the center of the first hollow (32c).

[0148] In addition, the first power supply unit (60a) can be formed to correspond to the diameter of the first coupling hole (15a) so that it can be inserted into a certain portion of the first coupling hole (15a) of the main frame body (11) and coupled thereto.

[0149] Accordingly, the first power coupling portion (61a) is coupled to a connecting groove (81a) formed on one side of the transmission body (81) of the power transmission portion (80) facing the first power supply portion (60a), and the power of the first power supply portion (60a) can be transmitted to the main gear (31) of the gear portion (30a) through the power transmission portion (80).

[0150] That is, the power provided from the first power supply unit (60a) is transmitted to the power transmission unit (80) connected to the connection groove (81a) and the first power coupling unit (61a), and the rotation of the power transmission unit (80) causes the main gear (31) connected to the fourth coupling unit (85) and the first hollow (32c) to rotate, and the rotation of the main gear (31) causes the first driven gear (33a) engaged with the main gear (31) to rotate, the second driven gear (33b) engaged with the first driven gear (33a) to rotate, and the third driven gear (33c) engaged with the second driven gear (33b) and connected to the driving wheels (20a, 20b, 20c) to rotate, thereby allowing the variable wheel movement device (1a) to travel.

[0151] In this way, each driving wheel (20a, 20b, 20c) is driven by the power provided from the first power supply unit (60a), so that the variable wheel moving device (1a) can travel on the ground.

[0152] The second power supply unit (60b) is connected to the main frame unit (10) and transmits power to the main frame unit (10) to rotate the main frame unit (10) at idle, thereby enabling the variable wheel movement device (1a) to ascend the stairs.

[0153] A second power coupling portion (61b) may be formed protrudingly at the center of one side of the second power supply portion (60b) to be connected to the main frame portion (10).

[0154] Specifically, the second power supply unit (60b) can be coupled to the second coupling hole (15b) formed on one side of the outer periphery of the first coupling unit (15) of the main frame unit (10) through the second power coupling unit (61b).

[0155] The second power coupling portion (61b) of the second power supply portion (60b) can be formed to correspond to the diameter of the second coupling hole (15b).

[0156] Accordingly, the power provided from the second power supply unit (60b) is transmitted to the main frame body (11) connected to the second power coupling unit (61b) and the first coupling unit (15), so that the main frame body (11) rotates, and by the rotation of the main frame body (11), each main frame (13a, 13b, 13c) formed by branches in the main frame body (11) can rotate.

[0157] In this way, the main frame part (10) can be rotated by the power provided from the second power supply part (60b) to climb the stairs.

[0158] The third power supply unit (60c) is connected to the sub-frame unit (40), and by rotating the sub-frame unit (40), the radius length from the center axis of the variable wheel moving device (1a) to the driving wheel unit (20) can be varied to correspond to the height and width of the stairs.

[0159] A third power coupling portion (61c) may be formed protrudingly at the center of one side of the third power supply portion (60c) to be connected to the sub-frame portion (40).

[0160] Specifically, the third power coupling part (61c) of the third power supply part (60c) can be connected to the third coupling part (47) of the sub-frame part (40), and a coupling groove (47a) for coupling the third power supply part (60c) can be formed in the third coupling part (47).

[0161] The third power coupling portion (61c) can be formed to correspond to the diameter of the coupling groove (47a).

[0162] Accordingly, the power transmitted from the third power supply unit (60c) is transmitted to the sub-frame unit (40), and branches are formed in the sub-frame body (41) of the sub-frame unit (40), and the first sub-frame (43a), the second sub-frame (43b), and the third sub-frame (43c) can rotate in one direction.

[0163] Accordingly, the first link (51a, 51b, 51c) and the second link (53a, 53b, 53c) connected to the spoke hole (45a, 45b, 45c) of each subframe (43a, 43b, 43c) by a fixed pin (75) can rotate in one direction.

[0164] In this way, when the sub-frame part (40) is rotated by receiving power from the third power supply part (60c), the first driven gear (33a) connected to the sub-frame part (40) rotates in one direction or the other direction and is arranged to be inclined with respect to the main frame (13), and the second driven gear (33b) connected to the first driven gear (33a) by the link part (50) is arranged to be inclined with respect to the main frame (13) in conjunction with the first driven gear (33a), and the second driven gear (33b) connected to the link part (50) rotates along the first driven gear (33a) so that the entirety can be arranged to be inclined.

[0165] And, the third driven gear (33c) connected to the second driven gear (33b) by the link portion (50), and connected to the link portion (50), the main frame portion (10), and each driving wheel (20a, 20b, 20c) by the wheel moving pin (71) can move in a straight line in the longitudinal direction in the slot portion (17a, 17b, 17c) of the main frame (13), so that the distance from each driving wheel (20a, 20b, 20c) to the central axis of the main frame portion (10) can be varied.

[0166] That is, the wheel moving pin (71) coupled to the slot portion (17a, 17b, 17c) of each main frame (13a, 13b, 13c) moves in the longitudinal direction of the slot portion (17a, 17b, 17c), and the driving wheel (20a, 20b, 20c) coupled to the end of the wheel moving pin (71) moves toward the main gear (31) or in the opposite direction to the main gear (31), so that the gap and distance between each driving wheel (20a, 20b, 20c) and the center of the subframe body (41) can be adjusted to decrease or increase.

[0167] Accordingly, the link part (50) rotates by the rotation of the sub-frame part (40), such as by rotating the sub-frame body (41) to correspond to the height and width of the stairs, thereby adjusting the distance and gap between each driving wheel (20a, 20b, 20c) and the central axis of the main frame part (10), and thus the length between the driving wheel (20a, 20b, 20c) and the central axis of the main frame part (10) or sub-frame part (40), i.e., the total length of the variable wheel moving device (1a), can be varied.

[0168] The pin section (70) may include a wheel moving pin (71) that connects the main frame section (10), the gear section (30a), the link section (50), the sub-frame section (40), and the driving wheel section (20), and rotates each driving wheel (20a, 20b, 20c) by driving the gear section (30a), and a fixed pin (75) that connects the link section (50), the gear section (30a), and the sub-frame section (40), and rotates the link section (50) and the gear section (30a) by rotating the sub-frame section (40).

[0169] Specifically, the wheel moving pin (71) is coupled to the slot portion (17a, 17b, 17c) of each main frame (13a, 13b, 13c), the first link hole (52) of each first link (51a, 51b, 51c), the second link hole (55) of each second link (53a, 53b, 53c), the spoke hole (45a, 45b, 45c) of each subframe (43a, 43b, 43c), and the wheel coupling groove (25) of each driving wheel (20a, 20b, 20c), but is most coupled to the driven gear (33) of the gear portion (30a) interposed between the first link (51a, 51b, 51c) and the second link (53a, 53b, 53c) in the main gear (31). It can be inserted and connected by penetrating into the second hollow (34c) of the third driven gear (33c) that is placed far away.

[0170] Accordingly, the wheel moving pin (71) can be formed with a diameter corresponding to the slot portion (17a, 17b, 17c), the first link hole (52), the second link hole (55), the spoke hole (45a, 45b, 45c), the wheel coupling groove (25), and the second hollow (34c).

[0171] Accordingly, the slot portion (17a, 17b, 17c), the first link hole (52), the second link hole (55), the spoke hole (45a, 45b, 45c), the wheel coupling groove (25), and the second hollow (34c) can be formed with the same diameter.

[0172] Here, the wheel moving pin (71) is installed so as to be movable along the longitudinal direction of the slot portion (17a, 17b, 17c) of each main frame (13a, 13b, 13c), thereby allowing each driving wheel (20a, 20b, 20c) to be moved on the slot portion (17a, 17b, 17c) of the main frame (13).

[0173] The wheel moving pin (71) is installed on the third driven gear (33c) which is positioned furthest from the main gear (31) among the plurality of driven gears (33), and can change the position of the third driven gear (33c).

[0174] Accordingly, each driving wheel (20a, 20b, 20c) connected to the third driven gear (33c) by a wheel moving pin (71) can have its position changed according to the movement of the wheel moving pin (71).

[0175] Meanwhile, in order to prevent the main frame part (10) connected to the wheel moving pin (71) by the slot part (17a, 17b, 17c) from being separated and detached, a stopper (73) in the form of a flange formed to be larger in size than the slot part (17a, 17b, 17c) may be integrally formed and extended at one end of the wheel moving pin (71).

[0176] Accordingly, the wheel moving pin (71) is positioned so that the stopper (73) is located on the other side of the slot portion (17a, 17b, 17c), and then is coupled by penetrating the slot portion (17a, 17b, 17c), the first link hole (52), the second hollow (34c), and the second link hole (55), and then coupled to the wheel coupling groove (25) of the driving wheel (20a, 20b, 20c), thereby allowing the main frame portion (10), the gear portion (30a), the link portion (50), the subframe portion (40), and the driving wheel portion (20) to be coupled.

[0177] The fixed pin (75) is inserted and fixed into the first link hole (52) of each first link (51a, 51b, 51c), the second link hole (55) of each second link (53a, 53b, 53c), and the spoke hole (45a, 45b, 45c) of each subframe (43a, 43b, 43c), and may be inserted and fixed by penetrating into the second hollow (34c) of the first driven gear (33a) interposed between the first link (51a, 51b, 51c) and the second link (53a, 53b, 53c).

[0178] In addition, the fixed pin (75) can be inserted and fixed by penetrating into the first link hole (52) positioned in the middle of the first link hole (52) of each of the first links (51a, 51b, 51c), the second link hole (55) formed in the first step portion (54a) among the second link holes (55) of each of the second links (53a, 53b, 53c), and the second hollow (34c) of the second driven gear (33b).

[0179] Accordingly, the fixed pin (75) can be installed on the first driven gear (33a) that is engaged with the main gear (31) among the plurality of driven gears (33) and the second driven gear (33b) that is engaged with the first driven gear (33a).

[0180] Here, the fixed pin (75) is formed with a diameter corresponding to the first link hole (52), the second link hole (55), the spoke holes (45a, 45b, 45c), and the second hollow (34c), and can be formed with a length corresponding to the combined thickness of the link portion (50), the gear portion (30a), and the subframe portion (40).

[0181] Accordingly, the fixed pin (75) can be formed with the same diameter as the first link hole (52), the second link hole (55), the spoke holes (45a, 45b, 45c) and the second hollow (34c).

[0182] Meanwhile, a connecting ring (91) may be installed on the outer periphery of the first connecting portion (15) of the main frame body (11), and the connecting ring (91) may be formed in a roughly O-ring shape by having a connecting hole (91a) formed through the center thereof with a size corresponding to the first connecting portion (15).

[0183] Here, the variable wheel movement device (1a) according to the present embodiment can operate independently or be installed and operated on a robot, and is not limited thereto and can be utilized in various other ways.

[0184] Hereinafter, the operation of the variable wheel movement device according to the present embodiment will be described with reference to FIGS. 4 to 6.

[0185] Fig. 4 is a drawing showing a driving mode in which the variable wheel travel device of Fig. 1 travels. Figs. 5a to 5c are drawings showing a climbing mode in which the variable wheel travel device of Fig. 1 travels while climbing stairs. Figs. 6a and 6b are drawings showing a variable mode in which the length of the variable wheel travel device of Fig. 1 is variable.

[0186] First, referring to FIG. 4, the driving mode of the variable wheel movement device (1a) according to the present embodiment will be described.

[0187] When power is transmitted from the first power supply unit (60a), the power transmission unit (80) coupled to the first power coupling unit (61a) of the first power supply unit (60a) rotates.

[0188] The main gear (31) coupled to the fourth coupling part (85) of the power transmission part (80) rotates by the rotation of the power transmission part (80).

[0189] By the rotation of the main gear (31), each first driven gear (33a) meshed with the main gear (31) rotates, and by the rotation of the first driven gear (33a), each second driven gear (33b) meshed with each first driven gear (33a) rotates, and by the rotation of the second driven gear (33b), each third driven gear (33c) meshed with each second driven gear (33b) and connected to each driving wheel (20a, 20b, 20c) rotates.

[0190] In this way, each driving wheel (20a, 20b, 20c) is rotated by the rotation of the third driven gear (33c), and the variable wheel moving device (1a) moves on the ground.

[0191] Referring to FIGS. 5a to 5c, the climbing mode of the variable wheel movement device (1a) according to the present embodiment will be described.

[0192] When power is transmitted from the second power supply unit (60b), the main frame unit (10) coupled to the second power coupling unit (61b) of the second power supply unit (60b) by the first coupling unit (15) rotates.

[0193] That is, as the main frame body (11) rotates, branches are formed from the main frame body (11), and the first main frame (13a), the second main frame (13b), and the third main frame (13c) rotate.

[0194] For example, as shown in the drawing, when the second driving wheel (20b) connected to the second main frame (13b) and the third driving wheel (20c) connected to the third main frame (13c) are positioned on the ground, and the first driving wheel (20a) connected to the first main frame (13a) is positioned above the second driving wheel (20b) and the third driving wheel (20c), and the third driving wheel (20c) comes into contact with the first riser formed vertically on the stairs during driving, power is transmitted from the second power supply unit (60b) to rotate the main frame unit (10).

[0195] At this time, the first driving wheel (20a) located above the second driving wheel (20b) and the third driving wheel (20c) rotates and comes into contact with the first step formed horizontally on the stairs, thereby ascending.

[0196] Accordingly, by the rotation of the main frame part (10), the first driving wheel (20a) and the third driving wheel (20c) are positioned on the first step, and the second driving wheel (20b) is positioned above the first driving wheel (20a) and the third driving wheel (20c).

[0197] Then, when the first driving wheel (20a) comes into contact with the second step again, the second driving wheel (20b) comes into contact with the second step by the rotation of the main frame (10), and thus, by the rotation of the main frame (13), a plurality of steps can be sequentially climbed through the first driving wheel (20a) connected to the first main frame (13a), the second driving wheel (20b) connected to the second main frame (13b), and the third driving wheel (20c) connected to the third main frame (13c).

[0198] Here, the ground contact and contact force with the ground and the stairs can be improved through a protrusion (not shown) formed on the outer periphery of each driving wheel (20a, 20b, 20c) to facilitate climbing the stairs.

[0199] Referring to FIGS. 6a and 6b, the variable mode of the variable wheel movement device (1a) according to the present embodiment will be described.

[0200] First, power is transmitted from the third power supply unit (60c) to the sub-frame unit (40) to rotate the sub-frame unit (40) to correspond to the height and width of the stairs to be climbed, and the distance and gap between the central axis of the sub-frame unit (40) and each driving wheel (20a, 20b, 20c) are set to the minimum length (L1) in the closest state, and then each driving wheel (20a, 20b, 20c) is rotated and driven by the power provided from the first power supply unit (60a), so that the variable wheel moving device (1a) is driven.

[0201] At this time, each driven gear (33) and the link part (50) connected to each driven gear (33) are rotated in one direction or the other direction and arranged to be inclined as a whole, so that the radius of the central axis of each driving wheel part (20) with respect to the central axis of the main frame part (10) can be made at the minimum distance and interval.

[0202] Here, when reaching a step exceeding the preset height and width while driving, the third power supply unit (60c) transmits power to the sub-frame unit (40) to rotate the sub-frame unit (40).

[0203] At this time, power is not supplied to each driving wheel (20a, 20b, 20c) from the first power supply unit (60a), and power is supplied to the sub-frame unit (40) only from the third power supply unit (60c).

[0204] By the rotation of the sub-frame part (40), a branch is formed in the sub-frame body (41), and the link part (50) connected to the spoke holes (45a, 45b, 45c) of the first sub-frame (43a), the second sub-frame (43b), and the third sub-frame (43c) by a fixing pin (75) is rotated so as to be arranged in a straight line with respect to each main frame (13a, 13b, 13c) of the main frame part (10).

[0205] Accordingly, the first to third driven gears (33a, 33b, 33c) connected to the first link (51a, 51b, 51c) and the second link (53a, 53b, 53c) rotate in correspondence with the link portion (50) in the gear portion (30a) interposed between the first link (51a, 51b, 51c) and the second link (53a, 53b, 53c).

[0206] And, the third driven gear (33c) connected to the wheel moving pin (71) slides on the slot portion (17a, 17b, 17c) of each main frame (13a, 13b, 13c), and the driving wheels (20a, 20b, 20c) connected to the third driven gear (33c) move toward the end portion of each main frame (13a, 13b, 13c).

[0207] Accordingly, when the sub-frame part (40) rotates, the link part (50) in which the driven gear (33) is interposed is arranged in a straight line with the main frame (13), and the distance and gap between the driving wheels (20a, 20b, 20c) and the central axis of the sub-frame body (41) are variably adjusted to correspond to the height and width of the stairs, such as by varying the distance and gap between the driving wheels (20a, 20b, 20c) and the central axis of the sub-frame body (41) to the maximum length (L2).

[0208] After adjusting the distance and gap between the driving wheels (20a, 20b, 20c) and the center axis of the subframe body (41), the stairs are climbed using the climbing mode.

[0209] When the distance and gap between the center axis of the driving wheel (20a, 20b, 20c) and the subframe body (41) are varied to a minimum length, the above process is performed in reverse to vary the length of the variable wheel movement device (1a).

[0210] Meanwhile, the driving wheels (20a, 20b, 20c), the gear portion (30a), and the link portion (50) are connected by a wheel moving pin (71), and the wheel moving pin (71) is made movable on the slot portion (17a, 17b, 17c) of each main frame (13a, 13b, 13c), so that the center axis distance of the driving wheels (20a, 20b, 20c) and the subframe body (41) is changed as the wheel moving pin (71) moves on the slot portion (17a, 17b, 17c).

[0211] Below, a variable wheel movement device according to a second embodiment of the present invention is described.

[0212] FIG. 7 is a rear perspective view showing a variable wheel movement device according to a second embodiment of the present invention.

[0213] Since the variable wheel moving device according to the present embodiment has the same structure as the variable wheel moving device according to the first embodiment described above, except for the gear part, a duplicate description of the same configuration will be omitted.

[0214] Referring to FIG. 7, the gear part (30b) of the variable wheel movement device (1b) according to the present embodiment may include a main gear (31'), a driven gear (33'), a driving gear (36), and a connecting member (38).

[0215] Specifically, the gear unit (30b) may include a main gear (31') connected to the central axis of the main frame body (11) through a power transmission unit (80), a driven gear (33') that is engaged with the main gear (31') and rotates in conjunction with the rotation of the main gear (31'), a drive gear (36) that is provided at a predetermined interval from the driven gear (33'), and a connecting member (38) that connects the driven gear (33') and the drive gear (36) so that the drive gear (36) rotates in conjunction with the driven gear (33').

[0216] Here, the driving gear (36) may have the same shape as the main gear (31') and the driven gear (33'), but is not limited thereto.

[0217] The connecting member (38) may be a connecting belt or a connecting chain.

[0218] Accordingly, when the main gear (31') rotates by the power transmitted from the first power supply unit (60a), each driven gear (33') meshed with the main gear (31') rotates, and when the driven gear (33') rotates, each driving gear (36) connected to each driven gear (33') by a connecting member (38) and connected to the driving wheels (20a, 20b, 20c) rotates, and accordingly, the driving wheels (20a, 20b, 20c) are rotated and the variable wheel moving device (1b) can be driven.

[0219] In addition, the sub-frame body (41) rotates by the power transmitted from the third power supply unit (60c), and each sub-frame (43) branched and formed on the sub-frame body (41) rotates, and each sub-frame (43) of the sub-frame body (41) rotates, and the driven gear (33') connected to the spoke hole (45a, 45b, 45c) formed in each sub-frame (43) by the rotation of each sub-frame (43) rotates in one direction or the other direction so as to be inclined with respect to the main frame (11), and the driving gear connected to each driving wheel (20a, 20b, 20c) by the wheel moving pin (71) moves linearly in the slot portion of the main frame, so that the distance and gap from each driving wheel to the central axis of the main frame portion can be adjusted.

[0220] Below, a variable wheel movement device according to a third embodiment of the present invention is described.

[0221] FIG. 8 is a drawing showing a variable wheel movement device according to a third embodiment of the present invention.

[0222] Since the variable wheel moving device according to the present embodiment has the same structure as the variable wheel moving device according to the first embodiment described above, except for the sensor unit and the control unit, a duplicate description of the same configuration will be omitted.

[0223] Referring to FIG. 8, the variable wheel movement device (1c) according to the present embodiment may further include a control unit (not shown) and a sensor unit (75).

[0224] The control unit can control the movement of the variable wheel travel device (1c) on the ground or floor surface.

[0225] Accordingly, the control unit can control the operation of the first power supply unit (60a).

[0226] The control unit can control the ascent of the variable wheel travel device (1c) on the stairs.

[0227] Accordingly, the control unit can control the operation of the second power supply unit (60b).

[0228] The control unit can vary the length of the variable wheel movement device (1c) to correspond to the height and width of the stairs.

[0229] Accordingly, the control unit can control the operation of the third power supply unit (60c).

[0230] Here, the control unit may be installed in the variable wheel movement device (1c), and may be a joystick or a remote control, but is not limited thereto.

[0231] At least one sensor unit (95) may be provided on the side of the main frame unit (10).

[0232] The sensor unit (95) may be formed of a detection sensor that can detect the height and width of steps when steps are detected during the driving of the variable wheel movement device (1c) according to the present embodiment.

[0233] Accordingly, the sensor unit (95) may be any one of an ultrasonic distance measuring sensor, an infrared distance detection sensor, and a laser detection sensor, but is not limited thereto.

[0234] In addition, in this embodiment, it is described as an example that the sensor unit (95) is provided on each side of the main frame unit (10), but the position and number of the sensor units (95) are not limited thereto and can be changed in various ways.

[0235] The sensor unit (95) is connected to the control unit wired or wirelessly and can transmit information data on the presence or absence of stairs and the height and width of the stairs to the control unit in real time.

[0236] Accordingly, the control unit can climb the stairs by adjusting the distance and gap between each driving wheel (20a, 20b, 20c) and the central axis of the main frame body (11) or sub-frame body (41) through the information data of the stairs provided through the sensor unit (95).

[0237] As described above, according to the present invention, a plurality of wheels are arranged radially and equiangularly, so that free movement is possible while maintaining efficient and stable driving performance on flat ground, and stairs can be easily climbed with power provided through a power supply unit, and the length from the central axis to the wheels is made variable to correspond to the height and width of the stairs, so that it can be transformed and varied into an optimized shape for stairs of various heights and widths, thereby having the effect of climbing stairs stably and smoothly.

[0238] While the present invention has been illustrated and described with reference to specific embodiments thereof, it will be readily apparent to those skilled in the art that various modifications and variations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A main frame section including a main frame body and a main frame branching and extending from the main frame body; A driving wheel section including a driving wheel drivably connected to an end of the main frame; A subframe portion including a subframe body and a subframe branching and extending from the subframe body; and It includes a link part that is rotatably connected between the driving wheel and the subframe, A variable wheel moving device characterized in that the radius of the central axis of the driving wheel part is changed with respect to the central axis of the main frame part by rotating the link part by rotating the subframe part.

2. In paragraph 1, The above main frame is formed by branching in N directions (N is a natural number) from the center of the main body of the above main frame, A variable wheel moving device, characterized in that the subframes are formed by branching off in the N direction from the center of the subframe body.

3. In paragraph 1, A gear unit interposed between the driving wheel unit and the main frame to transmit power; and A variable wheel moving device characterized in that it further includes a power supply unit including a first power supply unit that transmits power to the driving wheel unit, a second power supply unit that transmits power to the main frame unit, and a third power supply unit that transmits power to the subframe unit.

4. In the third paragraph, the link part, A variable wheel travel device characterized by including first and second links provided on each side of the gear section and rotating the gear section in conjunction with the subframe section.

5. In paragraph 4, The above first link extends in one direction and has a plurality of first through holes formed therein, A variable wheel moving device characterized in that the second link extends in one direction including a step portion and has a plurality of second through holes formed therein.

6. In paragraph 5, the step portion is A first step formed on one side of the second link and to which the gear portion is connected; and A variable wheel moving device characterized in that it includes a second step portion formed with a thickness smaller than the first step portion and to which the subframe is connected.

7. In paragraph 3, A variable wheel moving device further comprising a pin section including at least one fixed pin connecting the link section, the gear section, and the sub-frame section, and a wheel moving pin movably connecting the main frame section, the gear section, the link section, the sub-frame section, and the driving wheel section.

8. In paragraph 7, the main frame part, A first coupling portion protruding from the center of the main frame body and to which the first power supply portion is coupled; and A variable wheel moving device characterized in that it includes a slot portion formed along the extension direction of the main frame at the end of each main frame and through which the wheel moving pin moves.

9. In paragraph 8, A variable wheel moving device characterized in that a second coupling hole is formed in the first coupling portion to which the second power supply portion is coupled.

10. In paragraph 3, The driving wheel includes a wheel body, a wheel axle connected to the wheel body, and a wheel engaging groove formed on the wheel axle to which the wheel moving pin is engaged. A variable wheel moving device characterized in that the position of the driving wheel with respect to the central axis of the main frame part changes according to the movement of the wheel moving pin.

11. In paragraph 3, The above second power supply unit rotates the main frame unit, A variable wheel travel device characterized in that the third power supply unit rotates the sub-frame unit.

12. In the third paragraph, the gear part, a main gear rotatably connected to the first power supply unit; and A variable wheel moving device characterized by including a plurality of driven gears that are continuously gear-coupled to each other in one direction from the main gear and rotate in conjunction with the main gear.

13. In paragraph 12, The main gear rotates by the power provided from the first power supply unit, A variable wheel moving device characterized in that the driven gears rotate sequentially according to the rotation of the main gear, thereby driving the driving wheel connected to the driven gear.

14. In paragraph 12, A variable wheel moving device characterized in that the positions of the driven gears are changed as the sub-frame part rotates by the power provided from the third power supply part, so that the distance from the driving wheel to the central axis of the main frame part is changed.

15. In paragraph 12, The above driven gears include first to third driven gears, The above first driven gear is gear-coupled to the main gear and connected to the link portion and the subframe portion, The above second driven gear is gear-coupled to the above first driven gear and connected to the link portion, A variable wheel moving device characterized in that the third driven gear is gear-coupled to the second driven gear and connected to the main frame portion, the link portion, and the driving wheel portion.

16. In paragraph 15, The above first driven gear is connected to the link portion and the subframe portion by the fixed pin, The above second driven gear is connected to the above link part by the above fixed pin, A variable wheel moving device characterized in that the third driven gear is connected to the main frame section, the link section, and the driving wheel section by the wheel moving pin.

17. In paragraph 12, The above subframe body is coupled to the main gear and the third power supply unit, A variable wheel travel device characterized in that the subframe is coupled to the driven gear.

18. In paragraph 17, The subframe body and the main gear are connected by a second connecting portion formed on one side of the subframe body, A variable wheel travel device characterized in that the subframe body and the third power supply unit are connected by a third connecting portion formed on the other side of the subframe body.

19. In paragraph 12, A variable wheel travel device further comprising a power transmission unit that transmits power from the first power supply unit to the main gear.

20. In paragraph 19, the power transmission unit, Transmission body; A connecting groove formed on one side of the above transmission body and to which the first power supply unit is connected; and A variable wheel moving device characterized by including a fourth coupling part formed on the other side of the transmission body and coupled to the main gear.

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