Patent Application
20230406036
This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0073080 filed in the Korean Intellectual Property Office on Jun. 15, 2022, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a wheel structure, a method of controlling the wheel structure, and a mobility equipment including the wheel structure, and more particularly, to a wheel structure having a structure, which may be deformed actively in shape in accordance with a state of a ground surface on which the wheel structure moves, a method of controlling the wheel structure, and a mobility equipment including the wheel structure.
In the case of a low-speed mobility equipment such as a wheelchair, it is necessary to ensure traveling performance even in a case in which the mobility equipment travels on ground surfaces having various shapes. Studies on wheels mounted on the mobilities are being actively conducted to ensure the traveling performance.
For example, the mobility equipment needs to be equipped with a wheel having a structure capable of minimizing impact that is applied to the wheel from the ground surface and applied to an occupant when the ground surface on which the mobility equipment travels is not uniform.
In related art, spokes of the wheel are configured such that a length of each of the spokes varies depending on a state of the ground surface to ensure the performance. However, in related art, because the lengths of the spokes are independently changed, the responsiveness of the spokes to the state of the ground surface deteriorates, and components for independently controlling the lengths of the spokes are desired. For this reason, there is a problem in that a structure of the wheel is complicated.
The present disclosure has been made in an effort to provide a new type of wheel structure capable of independently controlling lengths of spokes by using a simple structure while changing the lengths of the spokes in accordance with a state of a ground surface on which the wheel structure moves.
A first aspect of the present disclosure provides a wheel structure including: a wheel including a portion provided in an outer region and extending in a circumferential direction C; a wheel driving unit configured to provide power for rotating the wheel about a central shaft A; a variable spoke configured to connect the wheel and the central shaft A and having a length that varies in a radial direction R of the wheel; a spoke driving unit configured to provide power for changing the length of the variable spoke in the radial direction R; and a power transmission unit configured to transmit power from the spoke driving unit to the variable spoke, in which the variable spoke is provided in plural, and the plurality of variable spokes is spaced apart from one another in the circumferential direction C, and in which the power transmission unit includes: an output shaft configured to rotate by receiving power from the spoke driving unit; and a clutch configured to dynamically connect the variable spoke and the output shaft and selectively transmit a rotational force of the output shaft to the variable spoke or cut off the transmission of the rotational force to the variable spoke.
The output shaft may be provided in plural, the clutch may be provided in plural, and the plurality of clutches may respectively connect the variable spokes and the output shafts.
The variable spoke may include: a first spoke region having one side fixed relative to the clutch; and a second spoke region coupled to the first spoke region and configured to be movable outward in the radial direction R by receiving a rotational force from the output shaft.
The output shaft may include: a shaft body extending in the radial direction R and having one side connected to the clutch; and a shaft gear fixedly coupled to the shaft body and having a serrated region formed on an outer portion thereof.
The power transmission unit may further include a ring gear having a serrated region that engages with the serrated region formed on the shaft gear.
The power transmission unit may further include an input shaft connected to the spoke driving unit and configured to be rotatable by receiving power from the spoke driving unit, and the ring gear may be fixedly coupled to an outer periphery of the input shaft.
The wheel may include: a plurality of leg regions respectively fixedly coupled to outer ends of the plurality of variable spokes based on the radial direction R; and a plurality of support regions each provided between the two leg regions adjacent to each other in the circumferential direction C, and two opposite ends of the leg region based on the circumferential direction C may be in contact with the support regions adjacent to the leg region.
The wheel may further include a connection region extending outward in the radial direction R from the central shaft A and configured to connect the central shaft and the support region.
The wheel may include a plurality of leg regions respectively fixedly coupled to outer ends of the plurality of variable spokes based on the radial direction R, and two opposite ends of any one of the leg regions based on the circumferential direction C may be in contact with other leg regions.
The wheel structure may further include: a restoring member configured to apply a force to the variable spoke in a direction in which the length of the variable spoke in the radial direction R decreases when the length of the variable spoke in the radial direction R increases.
The restoring member may be a gas spring.
The restoring member may be provided in parallel with the variable spoke and spaced apart from the variable spoke in a width direction W of the wheel structure.
The restoring member may be a band member having elasticity.
The power transmission unit may further include: a clutch-brake unit including the clutch and a brake configured to brake a motion of the variable spoke in a direction in which the length of the variable spoke decreases; a front end pulley member configured to connect the output shaft and the clutch-brake unit and transmit a rotational force of the output shaft to the clutch-brake unit; and a rear end pulley member configured to connect the variable spoke and the clutch-brake unit and transmit a rotational force of the clutch-brake unit to the variable spoke.
The power transmission unit may further include: a double clutch-brake unit including the clutch and a brake configured to brake a motion of the variable spoke in a direction in which the length of the variable spoke decreases; a first gear member fixedly coupled to the output shaft and having a serrated region formed on an outer surface thereof; a second gear member having a serrated region formed on an outer surface thereof and configured such that the serrated region engages with the serrated region of the first gear member; a connection shaft fixedly coupled to the second gear member; a first rear end pulley member configured to connect the double clutch-brake unit and the variable spoke and transmit a rotational force of the double clutch-brake unit to the variable spoke; and a second rear end pulley member configured to connect the connection shaft and the double clutch-brake unit and transmit a rotational force of the connection shaft to the double clutch-brake unit, and the clutch may include: a first clutch configured to connect the output shaft and the first rear end pulley member and selectively transmit a rotational force of the output shaft to the first rear end pulley member or cut off the transmission of the rotational force to the first rear end pulley member; and a second clutch configured to connect the second rear end pulley member and the first rear end pulley member and selectively transmit a rotational force of the second rear end pulley member to the first rear end pulley member or cut off the transmission of the rotational force to the first rear end pulley member.
The power transmission unit may further include: a brake configured to brake a motion of the variable spoke in a direction in which the length of the variable spoke decreases; a first gear member fixedly coupled to the output shaft, provided between the brake and the output shaft, and having a serrated region formed on an outer surface thereof; a second gear member having a serrated region formed on an outer surface thereof and configured such that the serrated region engages with the serrated region of the first gear member; a front end pulley member connected to the first gear member and configured to receive a rotational force of the first gear member; and rear end pulley members configured to connect the clutches and the variable spoke, the clutches may include: a first clutch connected to the front end pulley member; and a second clutch connected to the second gear member, and the rear end pulley members may include: a first rear end pulley member configured to connect the first clutch and the variable spoke; and a second rear end pulley member configured to connect the second clutch and the variable spoke.
A second aspect of the present disclosure provides a method of controlling a length of the variable spoke of the wheel structure during a process in which the wheel structure moves on a ground surface, the method including: a front length increasing step of increasing the length of the variable spoke provided in a front region of the wheel structure based on a traveling direction of the wheel structure; and a rear length decreasing step of decreasing the length of the variable spoke in a rear region of the wheel structure in a state in which the variable spoke has the length increased in the front length increasing step, the rear length decreasing step being performed after the front length increasing step.
The method may further include a length maintaining step of maintaining the length of the variable spoke in a state in which the variable spoke has the length increased in the front length increasing step, the length maintaining step being performed between the front length increasing step and the rear length decreasing step.
The method may further include: a front length decreasing step of decreasing the length of the variable spoke in the front region of the wheel structure in a state in which the variable spoke has the length increased in the front length increasing step, the front length decreasing step being performed after the front length increasing step; and a rear length increasing step of increasing the length of the variable spoke in the rear region of the wheel structure in a state in which the variable spoke has the length decreased in the front length decreasing step, the rear length increasing step being performed after the front length decreasing step.
A third aspect of the present disclosure provides a mobility equipment including: a wheel structure; and a frame to which the wheel structure is coupled, in which the wheel structure includes: a wheel including a portion provided in an outer region and extending in a circumferential direction C; a wheel driving unit configured to provide power for rotating the wheel about a central shaft A; a variable spoke configured to connect the wheel and the central shaft A and having a length that varies in a radial direction R of the wheel; a spoke driving unit configured to provide power for changing the length of the variable spoke in the radial direction R; and a power transmission unit configured to transmit power from the spoke driving unit to the variable spoke, in which the variable spoke is provided in plural, and the plurality of variable spokes is spaced apart from one another in the circumferential direction C, and in which the power transmission unit includes: an output shaft configured to rotate by receiving power from the spoke driving unit; and a clutch configured to connect the variable spoke and the output shaft and selectively transmit a rotational force of the output shaft to each of the plurality of variable spokes or cut off the transmission of the rotational force to each of the plurality of variable spokes.
According to the present disclosure, it is possible to provide a new type of wheel structure capable of independently controlling the lengths of the spokes by using the simple structure while changing the lengths of the spokes in accordance with a state of the ground surface on which the wheel structure moves.
Hereinafter, a wheel structure, a method of controlling the wheel structure, and a mobility equipment according to the present disclosure will be described with reference to the drawings.
Wheel Structure and Method of Controlling Wheel Structure
Referring to
In addition, the wheel structure 10 may further include a wheel driving unit 200 configured to provide power for rotating the wheel 100. More specifically, the wheel driving unit 200 may provide power for rotating the wheel 100 about a central shaft A. Therefore, the wheel driving unit 200 may be configured to provide power to move the wheel structure 10 on the ground surface. For example, the wheel driving unit 200 may be an electric motor, but the type of wheel driving unit 200 is not limited to the electric motor.
The wheel structure 10 may further include variable spokes 300 configured to connect the wheel 100 and the central shaft A and each having a length that may change in the radial direction R of the wheel 100. The variable spoke 300 may support at least a part of an outer region of the wheel 100 and move at least a part of the outer region of the wheel 100 in the radial direction R of the wheel structure 10. Therefore, as described below, the variable spokes 300 may allow the wheel structure 10 to move on the ground surfaces having various shapes and smoothly move upward or downward in a region with stepped portions such as stairs.
More specifically, as illustrated in
Referring to
Referring to
More specifically, referring to
More particularly, the output shaft 510 may be provided in plural, the clutch 520 may be provided in plural, the plurality of clutches 520 may respectively connect the variable spokes 300 and the output shafts 510. That is, according to the exemplary implementation of the present disclosure, the variable spoke 300, the output shaft 510, and the clutch 520 may correspond to one another in a one-to-one manner. Therefore, according to the present disclosure, when the lengths of some of the plurality of variable spokes 300 need to be increased during a process in which the wheel structure 10 moves, the clutches 520, which are dynamically connected to the variable spokes of which the lengths need to be increased, transmit the rotational forces of the output shafts 510, which are dynamically connected to the clutches, to the variable spokes of which the lengths need to be increased. Therefore, the lengths of the variable spokes may be increased. In contrast, the clutches 520 connected to the remaining variable spokes 300 cut off the transmission of the rotational forces from the output shafts 510, which are connected to the clutches 520, to the variable spokes. Therefore, the lengths of the remaining variable spokes 300 are not changed.
Meanwhile, as illustrated in
For example, as illustrated in
For example, the variable spoke 300 may include a telescopic ball screw, and the first to third spoke regions 310, 320, and 330 or the first and second spoke regions 310 and 320 may be fixedly coupled to a plurality of screw members that constitute the telescopic ball screw and are movable relative to one another. Therefore, when the telescopic ball screw receives the rotational force from the output shaft 510, the plurality of screw members moves in the radial direction R while rotating, such that the second spoke region 320 or the second and third spoke regions 320 and 330 may move outward in the radial direction R. In some implementations, known structures and operational principles can be used for the telescopic ball screw. Because the telescopic ball screw may smoothly operate not only in a direction in which a length thereof increases but also in a direction in which the length thereof decreases, there is an advantage in reducing or minimizing a force to restore the variable spoke 300, which has the increased length, to an original state, as described below.
Meanwhile, as illustrated in
Meanwhile, as illustrated in
Therefore, according to the present disclosure, when the input shaft 540 rotates by receiving power from the spoke driving unit 400, the ring gear 530 fixedly coupled to the input shaft 540 also rotates. Therefore, the output shaft 510, which engages with the ring gear 530 through the serrated regions, rotates. More particularly, the output shaft 510 may rotate in place about a central axis thereof without revolving around the input shaft 540. For example, a direction in which the shaft body 512 of the output shaft 510 extends may be perpendicular to a direction in which the input shaft 540 extends. For example, the input shaft 540, the output shafts 510, and the ring gear 530 may constitute a multi-axis gearbox in which a single input shaft and a plurality of output shafts correspond to one another.
Meanwhile, as illustrated in
According to one example of the present disclosure, because the leg region 110 is connected to the variable spoke 300, the leg region 110 may move outward in the radial direction R when the power from the spoke driving unit 400 is transmitted to the variable spoke 300 through the clutch 520. In contrast, the support region 120 may be fixed regardless of the movement of the leg region 110. That is, according to one example of the present disclosure, a distance between the support region 120 and the central shaft A of the wheel 100 may remain constant. To this end, according to one example of the present disclosure, the wheel 100 may further include connection regions 130 extending outward in the radial direction R from the central shaft A and configured to connect the central shaft A and the support regions 120. For example, the connection region 130 may be understood as a stationary spoke with a fixed length, unlike the variable spoke 300 with a variable length.
Referring to
In contrast, as illustrated in
Meanwhile, the wheel structure 10 according to the present disclosure may further include a configuration that restores the length of the variable spoke 300, of which the length is increased by power transmitted from the spoke driving unit 400, to the original state. More specifically, the wheel structure 10 may further include restoring members 600 each configured to apply a force to the variable spoke 300 in a direction in which the length of the variable spoke 300 in the radial direction R decreases in a state in which the length of the variable spoke 300 in the radial direction R has increased. More specifically, an inner end of the restoring member 600 based on the radial direction R may be fixedly coupled to the central shaft A, and an outer end of the restoring member 600 based on the radial direction R may be fixedly coupled to the outer region of the wheel 100, i.e., the leg region 110.
For example, as illustrated in
As illustrated in
Meanwhile, unlike the configuration illustrated in
The band member, which is used as the restoring member 600, may also be provided in parallel with the variable spoke 300 and spaced apart from the variable spoke 300 in the width direction W of the wheel structure 10. However, the band member, which is used as the restoring member 600, may extend in the radial direction R and surround a part of the outer periphery of the variable spoke 300. Alternatively, the band member may surround the outer periphery of the variable spoke 300 one or more times.
Meanwhile, the wheel structure 10 according to the present disclosure may further include brakes 525 (see
The clutch 520 and the brake 525 may be electronic components. Therefore, the power transmission implemented by the clutch 520 and the braking operation implemented by the brake 525 may be electronically controlled.
Hereinafter, various examples of the power transmission structure, which may be applied to the wheel structure 10 according to the present disclosure, will be described with reference to
As described above, as illustrated in
Referring to
In this case, the wheel structure 10 may further include: front end pulley members 900 each configured to connect the shaft body 512 of the output shaft 510 and the clutch-brake unit 550 and transmit a rotational force of the output shaft 510 to the clutch-brake unit 550; and rear end pulley members 1000 each configured to connect the variable spoke 300 and the clutch-brake unit 550 and transmit a rotational force of the clutch-brake unit 550 to the variable spoke 300.
According to the second example of the power transmission structure of the wheel structure 10 according to the present disclosure, when the length of the variable spoke 300 needs to be increased, the rotational force of the output shaft 510 may be transmitted to the variable spoke 300 through the front end pulley member 900, the clutch in the clutch-brake unit 550, and the rear end pulley member 1000. Thereafter, when the clutch cuts off the transmission of power to the variable spoke 300, the length of the variable spoke 300 is restored to the original length by the restoring member 600. In this case, when the brake in the clutch-brake unit 550 operates, the length of the variable spoke 300 may be maintained without being decreased. A process of controlling the length of the variable spoke 300 by using the brake will be described below when a method of controlling the wheel structure according to the present disclosure is described.
Meanwhile, referring to
In this case, the wheel structure 10 may further include: first gear members 810 each fixedly coupled to the shaft body 512 of the output shaft 510 and having a serrated region formed on an outer surface thereof; second gear members 820 each having a serrated region formed on an outer surface thereof and configured such that the serrated region engages with the serrated region of the first gear member 810; connection shafts 700 each fixedly coupled to the second gear member 820 and extending in one direction; first rear end pulley members 1010 each configured to connect the double clutch-brake unit 560 and the variable spoke 300 and transmit a rotational force of the double clutch-brake unit 560 to the variable spoke 300; and second rear end pulley members 1020 each configured to connect the connection shaft 700 and the double clutch-brake unit 560 and transmit a rotational force of the connection shaft 700 to the double clutch-brake unit 560.
In this case, the clutches in the double clutch-brake unit 560 may include: a first clutch configured to connect the output shaft 510 and the first rear end pulley member 1010 and selectively transmit a rotational force of the output shaft 510 to the first rear end pulley member 1010 or cut off the transmission of the rotational force to the first rear end pulley member 1010; and a second clutch configured to connect the second rear end pulley member 1020 and the first rear end pulley member 1010 and selectively transmit a rotational force of the second rear end pulley member 1020 to the first rear end pulley member 1010 or cut off the transmission of the rotational force to the first rear end pulley member 1010. More particularly, the first rear end pulley member 1010 and the second rear end pulley member 1020 may be indirectly connected to each other through a shaft coupled to the second clutch.
According to the third example of the power transmission structure of the wheel structure 10 according to the present disclosure, the rotational force of the output shaft 510 may be transmitted to the variable spoke 300 through a plurality of power transmission routes.
For example, in a case in which the length of the variable spoke 300 needs to be increased, the rotational force of the output shaft 510 is transmitted to the variable spoke 300 through the first clutch and the first rear end pulley member 1010. In contrast, the second clutch cuts off the power transmission.
Thereafter, in a case in which the length of the variable spoke 300 needs to be decreased, the rotational force of the output shaft 510 is transmitted to the variable spoke 300 through the first gear member 810, the second gear member 820, the connection shaft 700, the second rear end pulley member 1020, the second clutch, and the first rear end pulley member 1010. That is, because the first gear member 810 and the second gear member 820 engage with each other, a rotation direction of the output shaft 510 and a rotation direction of the second gear member 820 are opposite to each other. Therefore, a motion direction of the variable spoke 300 when the rotational force of the output shaft 510 is transmitted to the variable spoke 300 through the first clutch is opposite to a motion direction of the variable spoke 300 when the rotational force is transmitted to the variable spoke 300 through the second clutch. In particular, as illustrated in
Meanwhile, referring to
In addition, the wheel structure 10 may include: the first gear member 810 fixedly coupled to the shaft body 512 of the output shaft 510, provided between the brake 525 and the shaft body 512 of the output shaft 510, and having the serrated region formed on the outer surface thereof; the second gear member 820 having the serrated region formed on the outer surface thereof and configured such that the serrated region engages with the serrated region of the first gear member 810; the front end pulley member 900 connected to the first gear member 810 and configured to receive the rotational force of the first gear member 810; and the rear end pulley members 1000 configured to connect the clutches 520 and the variable spoke 300. More particularly, the front end pulley member 900 may be indirectly connected to the first gear member 810 through a separate rotary shaft, and the rear end pulley members 1000 may also be respectively and indirectly connected to the clutches 520 and the variable spoke 300 through separate rotary shafts.
Referring to
Similar to the third example of the power transmission structure, according to the fourth example of the power transmission structure of the wheel structure 10 according to the present disclosure, the rotational force of the output shaft 510 may be transmitted to the variable spoke 300 through the plurality of power transmission routes.
For example, in a case in which the length of the variable spoke 300 needs to be increased, the rotational force of the output shaft 510 is transmitted to the variable spoke 300 through the front end pulley member 900, the first clutch 521, and the first rear end pulley member 1010. In contrast, the second clutch 522 cuts off the power transmission.
Thereafter, in a case in which the length of the variable spoke 300 needs to be decreased, the rotational force of the output shaft 510 is transmitted to the variable spoke 300 through the first gear member 810, the second gear member 820, the second clutch 522, and the second rear end pulley member 1020. That is, a rotation direction of the first output shaft 510 and a rotation direction of the front end pulley member 900 are identical to each other, whereas a rotation direction of the output shaft 510 and a rotation direction of the second gear member 820 are opposite to each other because the first gear member 810 and the second gear member 820 engage with each other. Therefore, a motion direction of the variable spoke 300 when the power is transmitted to the variable spoke 300 through the first clutch 521 is opposite to a motion direction of the variable spoke 300 when the power is transmitted to the variable spoke 300 through the second clutch 522. Similar to the third example of the power transmission structure, even in the fourth example of the power transmission structure, there may be an advantage in that it is possible to more actively decrease the length of the variable spoke 300 in comparison with a case in which a speed at which the restoring member 600 (see
Hereinafter, the method of controlling the wheel structure according to the present disclosure will be described with reference to the above-mentioned description.
The method of controlling the wheel structure 10 according to the present disclosure may be applied to a case in which the wheel structure 10 moves in a region (e.g., a pit) recessed downward and disposed at a front side on the ground surface on which the wheel structure 10 moves. In particular, the method of controlling the wheel structure 10 according to the present disclosure is advantageous in allowing the wheel structure 10 to pass over the downwardly recessed ground surface while minimizing a change in height of the central shaft A of the wheel structure 10. In the present specification, a front region of the wheel structure 10 may be defined as a region positioned forward of a region in which the wheel structure 10 is in contact with the ground surface during a process in which the wheel structure 10 moves on the ground surface. A rear region of the wheel structure 10 may be defined as a region positioned rearward of the region in which the wheel structure 10 is in contact with the ground surface during a process in which the wheel structure 10 moves on the ground surface.
More specifically, the method of controlling the wheel structure 10 may include a front length increasing step of increasing the length of the variable spoke 300 provided in the front region of the wheel structure 10 when a downwardly recessed ground surface is present at a front side based on a traveling direction of the wheel structure 10. The front length increasing step may serve to increase ride quality of a mobility equipment having the wheel structure 10 by minimizing the downward movement of the wheel structure 10 by increasing the length of the variable spoke 300, which is to come into contact with the recessed ground surface, when the downwardly recessed ground surface is disposed forward of the wheel structure 10.
The front length increasing step may be performed by transmitting the power of the spoke driving unit 400 to the variable spoke 300 through the clutch. The front length increasing step may be performed by transmitting the rotational force of the output shaft 510 to the variable spoke 300 through the clutch 520 (see
In addition, the method of controlling the wheel structure 10 may further include a rear length decreasing step of decreasing the length of the variable spoke 300 in the rear region of the wheel structure 10 in the state in which the variable spoke 300 has the length increased in the front length increasing step. The rear length decreasing step is performed after the front length increasing step. The rear length decreasing step may serve to prepare the movement on the flat ground surface by allowing the variable spoke 300, which has the increased length and supports the downwardly recessed ground surface, to have the length in the original state again.
The rear length decreasing step may be performed as the length of the variable spoke 300 is decreased by the restoring member 600 in the state in which the clutch cuts off the transmission of power of the spoke driving unit 400. The rear length decreasing step may be performed by cutting off the transmission of the rotational force of the output shaft 510 to the variable spoke 300 through the clutch 520 (see
Meanwhile, according to the first example of the present disclosure, the rear length decreasing step of the method of controlling the wheel structure 10 may be performed immediately after the front length increasing step is ended. In this case, as illustrated in
In contrast, according to the second example of the present disclosure, the method of controlling the wheel structure 10 may further include a length maintaining step of maintaining the length of the variable spoke 300 in the state in which the variable spoke 300 has the length increased in the front length increasing step. The length maintaining step is performed between the front length increasing step and the rear length decreasing step. The length maintaining step may be performed as the brake operates in the state in which the transmission of the power of the spoke driving unit 400 to the variable spoke 300 is cut off. The length maintaining step may correspond to the situation in which the length of the variable spoke 300 is constantly maintained over time in section (b) in
In the case in which the length maintaining step is additionally performed as described above, the front length increasing step may be ended before the leg region 110 coupled to the variable spoke 300 with the increased length reaches the ground surface, and the rear length decreasing step may be started after the leg region 110 coupled to the variable spoke 300 with the increased length moves away from the ground surface. This is to implement the stable movement of the wheel structure 10 in the recessed ground surface by allowing the leg region 110 coupled to the variable spoke 300 to come into contact with the downwardly recessed ground surface in the state in which the length of the variable spoke 300 is constant after the length of the variable spoke 300 is completely increased.
Meanwhile, according to the third example of the present disclosure, the method of controlling the wheel structure 10 may further include a front length decreasing step of decreasing the length of the variable spoke 300 in the front region of the wheel structure 10 in the state in which the variable spoke 300 has the length increased in the front length increasing step. The front length decreasing step is performed after the front length increasing step. More specifically, according to the third example of the present disclosure, the front length increasing step may be performed until the leg region 110 coupled to the variable spoke 300 comes into contact with the ground surface, and the front length decreasing step may be performed until the leg region 110 moves to the rear region of the wheel structure 10 from a point in time at which the leg region 110 coupled to the variable spoke 300 begins to come into contact with the ground surface. This is to minimize a change in height of the central shaft A of the wheel structure 10 when the wheel structure 10 moves on the downwardly recessed ground surface. The front length decreasing step may correspond to the decrease in length of the variable spoke 300 over time in section (b) in
According to the third example of the present disclosure, the method of controlling the wheel structure 10 may further include a rear length increasing step of increasing the length of the variable spoke 300 in the rear region of the wheel structure in the state in which the variable spoke 300 has the length decreased in the front length decreasing step. The rear length increasing step is performed after the front length decreasing step. More specifically, according to the third example of the present disclosure, the rear length increasing step may be performed until the leg region 110 moves away from the ground surface from a point in time at which the leg region 110 coupled to the variable spoke 300 is moved to the rear region of the wheel structure 10, and the rear length decreasing step may be performed from a point in time at which the leg region 110 coupled to the variable spoke 300 moves away from the ground surface. This is to minimize a change in height of the central shaft A of the wheel structure 10 when the wheel structure 10 moves on the downwardly recessed ground surface. The rear length increasing step may correspond to the increase in length of the variable spoke 300 over time in section (c) in
Meanwhile,
Meanwhile, as illustrated, in the case in which the power transmission unit 500 includes the first and second clutches like the third and fourth examples of the power transmission structure, the restoring member 600 may not be provided because the second clutch transmits the power to the variable spoke 300 in the direction in which the length of the variable spoke 300 decreases.
Mobility Equipment
A mobility equipment (e.g., a mobile system) according to the present disclosure may be a mobility equipment that travels at low speed. For example, the mobility equipment according to the present disclosure may be an electric wheelchair.
The mobility equipment according to the present disclosure may include the wheel structure 10, and a frame to which the wheel structure is coupled.
The wheel structure 10 may include: the wheel 100 including a portion provided in the outer region of the wheel structure 10 and extending in the circumferential direction C; the wheel driving unit 200 configured to provide power for rotating the wheel 100 about the central shaft A; the variable spokes 300 configured to connect the wheel 100 and the central shaft A and each having the length that varies in the radial direction R of the wheel 100; the spoke driving unit 400 configured to provide power for changing the lengths of the variable spokes 300 in the radial direction R; and the power transmission unit 500 configured to transmit power from the spoke driving unit 400 to the variable spoke 300.
In addition, the variable spoke 300 may be provided in plural, and the plurality of variable spokes 300 may be spaced apart from one another in the circumferential direction C. The power transmission unit 500 may include: output shafts 510 configured to rotate by receiving power from the spoke driving unit 400; and clutches 520 configured to connect the variable spokes 300 and the output shafts 510, the clutches 520 being configured to selectively transmit rotational forces of the output shafts 510 to the plurality of variable spokes 300 or cut off the transmission of the rotational forces to the plurality of variable spokes 300. Meanwhile, the description of the wheel structure 10 according to the present disclosure described with reference to the drawings may also be equally applied to the mobility equipment according to the present disclosure.
The present disclosure has been described with reference to some implementations and the drawings, but the present disclosure is not limited thereby. The present disclosure may be carried out in various forms by those skilled in the art, to which the present disclosure pertains, within the technical spirit of the present disclosure and the scope equivalent to the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1020220073080 | Jun 2022 | KR | national |
