Wheel comprising independently rotatable hub and shape-adaptable rim

Abstract

A wheel comprises: at least two hubs along an axis of rotation of the wheel; the rim is adaptive in shape; and a plurality of rigid struts extending outwardly from the hub to the rim. Each hub is independently rotatable about the axis. Each strut has a first end pivotably connected to one of the hubs and a second end pivotably connected to the rim.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority of U.S. Provisional Application No. 63 / 420,050, filed Oct. 27, 2022, the content of which is incorporated herein by reference. Background of the Invention

[0003] Pneumatic tires are used on various ground vehicles such as wheelchairs, bicycles, automobiles, and trucks. Pneumatic tires absorb the shock between the vehicle and the road. For example, when a vehicle travels over a bump in the road, the pneumatic tire deforms to limit vertical travel. A vehicle may be equipped with springs that limit vertical travel when traveling over larger bumps, and shock absorbers that dampen such movement for better recovery after larger bumps.

[0004] Pneumatic tires have certain disadvantages: they can leak air when punctured by sharp objects, the tire pressure must be maintained, and pneumatic tires must be replaced after their tread wears below a certain level.

[0005] Numerous attempts have been made to replace the pneumatic characteristics of a rigid rim and its locally compliant suspension between the contact points with the ground. Summary of the Invention

[0006] According to one embodiment, a wheel includes: at least two hubs along a rotational axis of the wheel; a shape-adaptable rim; and a plurality of rigid struts extending outwardly from the hubs to the rim. Each hub is rotatable independently about the axis. Each strut has a first end pivotally connected to one of the hubs and a second end pivotally connected to the rim. Brief Description of the Drawings

[0007] When read in conjunction with the following specification, reference will now be made to the drawings, in which like reference numerals refer to like parts throughout the several views, and in which:

[0008] Figure 1A is a view of a wheel including independent hubs and a flexible rim according to a first embodiment.

[0009] Figure 1B is Figure 1A a view of the hubs and struts of the wheel.

[0010] Figure 2A 、 2B and 2C are views of different shapes of the rim during operation of the wheel of Figure 1A the wheel.

[0011] Figure 3 is a view of an attachment bracket on the rim.

[0012] Figure 4 It is a view of a wheel including an independent hub and a flexible rim according to the second embodiment.

[0013] Figure 5 It is a view of a wheel including an independent hub and a flexible rim according to the third embodiment.

[0014] Figure 6A and 6B 6C are views of different shapes of the rim during the operation of the wheel in Figure 5 It is a view of the rim shapes comparing different node designs.

[0015] Figure 7 It is a view of the rim shapes comparing different node designs.

[0016] Figure 8A and 8B 9 and 10 are views of a wheel including an independent hub and a segmented rim according to the fourth embodiment, where Figure 10 shows a partially removed portion of the first hub and the strut.

[0017] Figure 11 is a view of a joint formed by adjacent rim segments and struts of the wheel in Figure 10 It is a view of a joint formed by adjacent rim segments and struts of the wheel in

[0018] Figure 12 It is a block diagram of a vehicle according to the first embodiment.

[0019] Figure 13 It is a view of an automotive suspension according to the first embodiment. Detailed Description

[0020] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, like reference numerals generally identify like components unless the context dictates otherwise. The illustrative embodiments described in the detailed description, the drawings, and the claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made without departing from the spirit or scope of the subject matter presented herein.

[0021] Referring to Figure 1A . The wheel 110 includes an axle 120 that defines a rotational axis and a rotational plane (the axis is perpendicular to the plane). The wheel 110 further includes first and second hubs 130 and 140 spaced apart along the axle 120. Each hub 130 and 140 is configured to rotate independently about the axle 120 and thus independently about the rotational axis. For example, bearings may be used to allow the hubs 130 and 140 to rotate relative to the axle 120.

[0022] In Figure 1AIn the illustrated embodiments, each of the hubs 130 and 140 has a central portion and arms extending radially outwardly from the central portion. For each of the hubs 130 and 140, the arms are equally angularly (i.e., 120 degrees) spaced about the central portion.

[0023] A torsion spring 150 is coupled between the first hub 130 and the second hub 140. The shaft 120 extends through the torsion spring 150. A first end of the torsion spring 150 is fastened to the first hub 130, and a second end of the torsion spring 150 is fastened to the second hub 140. For example, the torsion spring 150 may have spring stops positioned within openings in the hubs 130 and 140. The torsion spring 150 is operative to resist winding and unwinding forces and, in so doing, resists forces that would cause the hubs 130 and 140 to rotate relative to each other. When wound, the torsion spring 150 stores mechanical energy.

[0024] The wheel 110 further includes a rim 160 located in the plane of rotation. The rim 160 is continuous and flexible. The flexibility can be achieved by selecting a material and wall thickness. As discussed below, the flexible rim 160 should be able to deform during operation without breaking, remain within its plane of rotation, and not absorb excessive energy when changing shape.

[0025] The wheel 110 further includes a plurality of elongate rigid struts 170 extending between the hubs 130 and 140 to the rim 160. The struts 170 are designed for tension and compression. Each strut 170 has a first end pivotally connected to one of the arms of either the hub 130 or 140 and a second end pivotally connected to the rim 160. The pivot axes at the attachments to the rim 160 and the hubs 130 and 140 are perpendicular to the plane of rotation. The struts 170 transmit forces between the rim 160 and the hubs 130 and 140.

[0026] In Figure 1A the three-node design illustrated, three struts 170 are pivotally connected to the first hub 130, and three struts 170 are pivotally connected to the second hub 140. The second ends of the struts 170 are equally angularly spaced about the rim (i.e., spaced 60 degrees apart). All six struts 170 have equal lengths.

[0027] Figure 2A 、 2B Figures 2A, 2B, and 2C illustrate different shapes of the wheel 110. As used herein, the operating load includes the downward force on the hubs 130 and 140 toward the ground. For example, the operating load may be applied via the shaft 120. For example, the shaft 120 may carry the weight of the vehicle.

[0028] Figure 2AShows the wheel 110 in an undisturbed state, where no operating load is applied to the hubs 130 and 140, and no force that causes the hubs 130 and 140 and the rim 160 to rotate about the axis 120. Also refer to Figure 1B , each strut 170 is substantially perpendicular to its associated arm 132, 142. For a line L that radially extends from the axis of rotation A (defined by the axis 120) through the pivot axis P at the first end of the strut 170, the strut 170 is substantially perpendicular to the line L.

[0029] The hubs 130 and 140 are angularly offset. The arms of the first hub 130 are angularly spaced from the arms of the second hub 140 (i.e., spaced 60 degrees). Thus, the rim 160 has a circular shape.

[0030] At least one pivot is off-center on each of the hubs 130 and 140. When an operating load F is applied to the hubs 130 and 140, the hubs 130 and 140 are forced to rotate in reverse. The shape of the rim 160 begins to change, transitioning from the shape shown in Figure 2A to the shape shown in Figure 2B and then to the shape shown in Figure 2C .

[0031] Figure 2B Shows that during reverse rotation, the arms of the first hub 130 move closer to being aligned with the arms of the second hub 140. The torsion spring 150 resists this reverse rotation and stores mechanical energy. The struts 170 transmit forces to the rim 160 that cause the rim 160 to deform. The struts 170 connected to the first hub 130 push the rim 160, while the struts 170 connected to the second hub 140 pull the rim 160. The shape of the rim 160 is no longer circular.

[0032] Figure 2C Shows that the arms of the hubs 130 and 140 are now aligned, and the rim 160 has been adapted to an overall rounded polygon shape, and specifically a rounded triangle shape. The rounded triangle has three nodes. The rim 160 now has a relatively flat contact surface on the ground.

[0033] If the operating load is removed from the axis 120, then the torsion spring 150 forces the hubs 130 and 140 and the struts 170 back to the position of Figure 2A , thereby causing the rim to return to the circular shape of Figure 2A .

[0034] As the rim 160 rotates, the different struts 170 maintain a rounded triangular shape. Thus, as the wheel 110 moves along the ground, different portions of the rim 160 contact the ground, but the rim 160 maintains its rounded triangular shape and its contact surface. If the force F remains constant and the rim encounters no interference (e.g., a bump), then the rounded triangular shape does not change. In effect, a rolling flat spot is achieved.

[0035] When subjected to impacts or pressures against the ground, a wall, or a curb, occurring in any direction, the rim 160 deforms, along with varying suspension forces and shock absorption. The torsion springs 150 provide a restoring force that replaces the air pressure "spring" of an inflated tire. The torsion springs 150 allow the hubs 130 and 140 to move and enable the rim 160 to deform to overcome small bumps without forcing the axle 120 to rise.

[0036] The rolling flat spot of the rim 160 generally provides greater ground contact than conventional wheels and inflated tires, thus improving travel on unimproved surfaces. The shape of the rim 160 changes without modifying the surface length. The rim 160 does not require an ideal circular shape.

[0037] The operating load can lower the height of the axle 120 by ten to forty percent. This provides an additional suspension effect.

[0038] The wheel 110 eliminates the need for an inflated tire. The elimination of the inflated item makes the wheel 110 lighter, stronger, puncture-proof, and much simpler to manufacture.

[0039] The wheel in this document is not limited to Figure 1A the embodiments. The struts 170 can be attached to the rim 160 in various ways. Figure 3 An example is shown where the bracket 310 is attached to (e.g., spot welded to) the inner surface 320 of the rim 160 or is integrally formed with the inner surface 320 of the rim 160. A pin (not shown) is inserted through the hole 330 in the bracket 310 and the pin hole at the second end of the strut 170.

[0040] The wheel in this document is not limited to six struts 170. The Figure 1A wheel can be modified by increasing the number of struts 170. A greater number of struts 170 will apply a more uniform force to the rim 160 and will allow the wheel 110 to have a greater load-carrying capacity.

[0041] A greater number of struts will also be beneficial for wider rims. The additional struts can prevent the rim from twisting too far out of the plane of rotation.

[0042] Refer to Figure 4, which shows a three - node wheel 410 having twelve struts 470. The first ends of six struts 470 are pivotally connected to a first hub 430, and the first ends of the other six struts 470 are pivotally connected to a second hub 440. The second ends of the struts 470 are pivotally connected to the rim 460 in an alternating sequence (struts 470 from the first hub 430, struts 470 from the second hub 440, struts 470 from the first hub 430, and so on). The angular spacing between the struts 470 at the rim 460 is 30 degrees. The angular spacing of the arms on each of the hubs 430 and 440 is 60 degrees.

[0043] Unlike Figure 1A the wheel 110, Figure 4 the wheel 410 has intersecting struts 470. There is still one strut 470 per node, where each strut extends to the corner of the maximum deformation shape at the maximum distance from the axis 420. The additional struts 470 act in a way that minimizes the distance from the axis 420. The intersecting struts 470 provide a way to push and pull the rim 460 from the same hubs 430, 440. For example, the first hub 430 can push a first group of struts attached to the rim nodes while the first hub simultaneously pulls a second group of struts attached to a position between the nodes (e.g., midway). In other words, the use of intersecting struts 470 provides a way to deform the rim 460 by pushing and pulling from the same hubs 430, 440.

[0044] The wheels in this document are not limited to a three - node design. Other embodiments of the wheels in this document can have two nodes or more than three nodes. Generally, fewer nodes can achieve more extreme axle drop (which determines the suspension limit). Increasing the number of nodes increases the number of struts per hub, which can increase the load - carrying capacity and rim strength.

[0045] Refer to Figure 5 , which shows a wheel 510 having a two - node design. Four hubs 530, 535, 545, and 540 can rotate independently about an axis 520. Each of the hubs 530, 535, 545, and 540 has two arms. The wheel 510 has eight struts 570. Each strut 570 has a first end pivotally connected to one of the arms and a second end pivotally connected to the rim 560.

[0046] The inner hubs 535 and 545 are coupled by a torsion spring 550. If desired, the suspension can be further enhanced by coupling a second torsion spring between the hubs 535 and 530 and a third torsion spring between the hubs 540 and 545.

[0047] Figure 6A , 6B and 6C illustrate different shapes of the rim 560 during the operation of the wheel 510. Figure 6AShows the wheel 510 in an undisturbed state, where no downward force is applied to the axle 520 and no force causes the hubs 530, 535, 540, and 545 and the rim 560 to rotate about the axle 520. Each strut 570 is substantially perpendicular to the line passing through the pivot point and the axis of rotation. The hubs 530 and 535 are nearly aligned. The hubs 540 and 545 are offset. Thus, the rim 560 has a circular shape.

[0048] Figure 6B Shows the wheel 510 when a downward force F is applied to the axle 520. The hubs 530 and 535 rotate in opposite directions out of alignment, and the hubs 545 and 540 rotate in the opposite direction towards alignment. Those struts 570 attached to the hub 530 push the rim 560. Those struts 570 attached to the other hubs 535, 540, and 545 start to pull the rim 560. Thus, the rim 560 is slightly oval-shaped.

[0049] Figure 6C Shows the wheel 510 when the downward force F continues to be applied to the axle 520. The hubs 530 and 535 have rotated in opposite directions out of alignment, and the hubs 540 and 545 have rotated in opposite directions into nearly alignment. Thus, the rim 560 has an elliptical shape with a large contact surface on the ground. The maximum deformation of this design is about 40% of the radius.

[0050] Figure 7 Shows the superposition of the circular shape 700 and different rounded polygon shapes for different node designs. The two-node design has an elliptical shape 710, the three-node design has a triangular shape 720, the six-node design has a hexagonal shape 730, and the nine-node design has a nonagonal shape 740. Although not shown, the four-node design has a square shape, the five-node design has a pentagonal shape, the seven-node design has a heptagonal shape, and the eight-node design has an octagonal shape. Note that each polygon shape 710, 720, 730, and 740 has the same perimeter as the circular shape 700.

[0051] Figure 7 Also shows a comparison of the suspension drop for different node designs. The elliptical shape 710 has the largest drop Δ, and as the number of nodes increases, the suspension drop becomes smaller.

[0052] The three-node design is not limited to two hubs, and the two-node design is not limited to four hubs. The number of hubs depends on considerations such as the rim width. A wider rim is more likely to distort out of plane. Additional hubs will allow the addition of additional struts to provide a more uniform force distribution on a wider rim and provide greater support to prevent the rim from distorting. For example, Figure 1A the wheel 110 of can be modified to have a very wide rim, a pair of hubs added outside the axle 120, and the number of struts doubled.

[0053] The wheels in this document are not limited to having Figure 1A the shape shown in Figure 5 or the hub having the shape shown in . For example, the hub may have a circular shape.

[0054] Although FIGS. 1, 4, and 5 show wheels 110, 410, and 510 having struts 170, 470, and 570 of equal length, the wheels in this document are not limited thereto. The wheels in this document may have struts of different lengths. The shorter length struts may be pivotally connected to the longer length arms, while the longer length struts may be pivotally connected to the shorter length arms.

[0055] Figure 2A and 6A show struts 170 and 570 which, when no operating load is applied to wheels 110 and 510 and the rims 160 and 560 are circular, are substantially perpendicular to their connecting arms. Perpendicularity is preferred because the maximum force is initially applied along the longitudinal axes of struts 170 and 570. However, the struts are not limited to being perpendicular. Additionally, when an operating load is applied to wheels 110 and 510, struts 170 and 570 will rotate through a range of angles. For example, Figure 5 strut 570 will rotate through an angular range from approximately 30 degrees to 180 degrees.

[0056] The wheels in this document are not limited to a continuous and flexible rim. Generally, the wheels in this document have a rim whose shape can be adapted. A flexible rim is one example of a shape - adaptable rim. Another example is a segmented rim.

[0057] Now refer to Figure 8A , 9 and 10, which show a wheel 810 having a segmented rim 860. Wheel 810 includes an axle 820 which defines a rotational axis A. Wheel 810 further includes a first hub 830 and a second hub 840, the first hub 830 and the second hub 840 being configured to rotate independently about the axle 820. Each hub 830 and 840 has a disc shape.

[0058] In Figure 10 , a portion of the first hub 830 is removed to expose a torsion spring 850. The axle 820 extends through the torsion spring 850, the first end of the torsion spring 850 being fastened to the first hub 830, and the second end of the torsion spring 850 being fastened to the second hub 840.

[0059] Additionally refer to Figure 11。The segmented rim 860 includes a plurality of rim segments 862. Each rim segment 862 has a solid arcuate body 864 that has hinge rings 866 and 868 at opposite ends. The hinge ring 866 of each rim segment 862 mates with the hinge ring 868 of an adjacent segment 862.

[0060] The wheel 810 further includes twelve rigid struts 870 extending from the hubs 830 and 840 to the rim 860. The distal end of each strut 870 has a pin hole 872. The pin hole 872 is aligned with a hole in the mating rings 866 and 868, and a pin 869 is inserted through the aligned holes. Thus, not only are adjacent rim segments 862 hinged about a pivot point, but the second ends of the struts 870 are also hinged about the pivot point.

[0061] The first end of the strut 870 has a pin hole for receiving a pin that is fastened to the hub 830 or 840. In this way, the strut 870 is pivotally connected to the hubs 830 and 840.

[0062] The wheel 810 has a three-node design. A first group of six struts 870 n are pinned to the rim 860 at the node location, and a second group of six struts 870 w are pinned to the rim 860 at the intermediate wall location (the indices n and w refer to node and wall, respectively). The cross struts can be offset from the hubs 830 and 840 by spacers. When no operating load is applied to the shaft 820, each strut 870 is generally tangent to its hub 830 or 840, and the rim 860 has a circular shape.

[0063] Now also refer to Figure 8B 。When a downward force is applied to the shaft 820, the hubs 830 and 840 rotate in opposite directions, and a first group of six struts 870 n push against the rim 860 to form a node, and a second group of six struts 870 w pull on the rim 860 to form a wall, causing the rim 860 to have a rounded triangular shape 880 and a large contact surface 890 on the ground.

[0064] The wheels in this document are not limited to torsion springs between the hubs. Components other than torsion springs can be used to limit the relative rotation of the first and second hubs. For example, the rotational force between the hubs can be impeded by a hydraulic circuit that forces hydraulic fluid to flow through restricted orifices.

[0065] The outer surface of the rim 860 can be covered or uncovered. For example, the rim can be covered with a rubber tread.

[0066] The wheels in this document are not limited to any particular vehicle. Examples of vehicles include, but are not limited to, tractors, cars, bicycles, wheelchairs, and scooters.

[0067] Refer to Figure 12, which is a block diagram of a vehicle 1210. The vehicle 1210 includes a body 1220, an optional suspension 1230 for supporting the body 1220, and a set of wheels 1240 as described herein. The wheels 1240 can be directly coupled to the body 1220 or indirectly coupled to the body 1220 via the suspension 1230. The number and design of the wheels 1240 of the vehicle 1210 will depend on the size and weight of the vehicle 1210, the terrain on which the vehicle 1210 will operate, and the like.

[0068] The wheels 1240 eliminate the need for pneumatic tires. The elimination of pneumatic items makes the wheels 1240 lighter, stronger, puncture-proof, and much simpler to manufacture.

[0069] The wheels 1240 have the ability to fold suspension and shock absorption features into the wheels 1240. In some embodiments, the suspension can be eliminated.

[0070] With or without the suspension 1230, the wheels 1240 provide weight and space saving design options.

[0071] Now also referring to Figure 13 , Figure 13 shows a portion of an automotive suspension 1230 and, by way of example only, a wheel 1240 having the three-node, six-strut design of FIG. 1. The wheel 1240 is mounted to a frame 1310. For example, the axle 120 of the wheel 1240 is securely mounted to the frame 1310. The hubs 130 and 140 pivot independently on the axle 120. The rear wheels 1240 are driven via a differential. Even when the rear wheels 1240 turn at different rates when the vehicle 1210 is turning, the two rear wheels 1240 maintain their contact surfaces.

[0072] Because each wheel 1240 also provides shock absorption when the rim 160 collapses into its compressed shape in response to forces acting towards the axle 120 from any direction, the suspension springs can be eliminated or made smaller than the springs of a conventional suspension system.

[0073] Each wheel 1240 has a suspension limit D. If the wheel 1240 hits a speed bump or other protrusion in the road, the resulting vibration will cause the rim to bend and apply a torsional spring force to the axle 120. If the suspension limit D is not exceeded, then the axle 120 will not rise and no force will be transmitted to the body 1220.

[0074] The suspension 1230 can further include a shock absorber 1320 coupled between the arms of the first hub 130 and the second hub 140. The shock absorber 1320 dampens spring oscillations.

[0075] For a vehicle 1210 such as a tractor, the wheels 1240 can be smaller than conventional wheels and pneumatic tires and still provide a large contact surface. This provides the additional benefit of reducing the height of such vehicles. For example, a tractor equipped with two wheels 1240 at the rear will have an advantage when loading / unloading, or when entering a storage area with limited space, or when attempting to drive under a fixed bridge.

[0076] The wheels 1240 provide increased mobility on rough terrain through an in-built suspension and shock absorber. This is particularly valuable for vehicles such as wheelchairs and bicycles.

[0077] The wheels in this document are not even limited to vehicles. Other uses include conveyor belts and transmissions. The conveyor belt itself can have an in-built shock absorber. The transmission can utilize the constant perimeter feature of the wheel, where the wheel can change the diameter at which the tension is applied. Consider a bicycle pedal crank and derailleur setup that moves the chain from one sprocket to another while managing slack. This mechanism can be replaced by front and rear flexible rim wheels, where a lightweight cable is wound around the crank such that no slack needs to be created as the front and rear components change shape. As explained above, regarding Figure 7 , the various shapes of the rim have the same perimeter. Therefore, no slack is created in the cable. This would be a continuously variable transmission.

[0078] Example 1 can include a wheel having a rotational axis, the wheel comprising: at least two hubs along the rotational axis, each hub being rotatable independently about the axis; a shape-adaptable rim; and a plurality of rigid struts extending outwardly from the hubs to the rim, each strut having a first end pivotally connected to one of the hubs and a second end pivotally connected to the rim.

[0079] Alternatively and / or additionally, Example 2 includes Example 1, wherein the rotational axis is perpendicular to the plane of rotation, and wherein the struts pivot along an axis that is also perpendicular to the plane of rotation.

[0080] Alternatively and / or additionally, Example 3 includes one or more of Examples 1 to 2, wherein the hubs and struts are configured to cause reverse rotation of the hubs when an operating load is applied to the hubs.

[0081] Alternatively and / or additionally, Example 4 includes one or more of Examples 1 to 3, wherein the struts are attached to the hubs to form at least one eccentric pivot on each hub to cause the reverse rotation.

[0082] Alternatively and / or additionally, Example 5 includes one or more of Examples 1 to 4, wherein the reverse rotation causes a first group of the struts to push the rim to form nodes, and a second group of the struts to pull the rim to form sides, thereby causing the rim to adapt to a rounded polygon shape.

[0083] Alternatively and / or additionally, Example 6 includes one or more of Examples 1 to 5, wherein the rounded polygon shape includes a rolling flat spot during rotation of the rim.

[0084] Alternatively and / or additionally, Example 7 includes one or more of Examples 1 to 6, wherein the wheel has a three-node design.

[0085] Alternatively and / or additionally, Example 8 includes one or more of Examples 1 to 7, wherein in the absence of operating loads on the wheel, the rim has a circular shape and each strut is substantially perpendicular to a line extending radially from the axis of rotation through the pivot axis at the first end.

[0086] Alternatively and / or additionally, Example 9 includes one or more of Examples 1 to 8, which further includes a member for resisting relative rotation of the hubs.

[0087] Alternatively and / or additionally, Example 10 includes one or more of Examples 1 to 9, which further includes a torsion spring coupled between the hubs.

[0088] Alternatively and / or additionally, Example 11 includes one or more of Examples 1 to 10, wherein the at least two hubs include a first hub and a second hub; wherein a first group of the struts is pivotally connected to the first hub and a second group of the struts is pivotally connected to the second hub; wherein reverse rotation of the first hub and the second hub causes the first group of struts to push against the rim to form nodes and the second group of struts to pull the rim to form a circular wall; and wherein the first group of the struts includes one strut for each of the nodes.

[0089] Alternatively and / or additionally, Example 12 includes one or more of Examples 1 to 11, wherein the rim is flexible and continuous.

[0090] Alternatively and / or additionally, Example 13 includes one or more of Examples 1 to 12, wherein the rim includes a plurality of arcuate segments, wherein ends of adjacent segments are hinged at pivot points, and wherein the second ends of the struts are also hinged at the pivot points.

[0091] Example 14 may include a method for a wheel having a shape-adaptable rim and a plurality of struts pivotally attached to the rim, the method including: pushing a first group of the struts to form nodes of a rounded polygon shape; and pulling a second group of the struts to form sides of a rounded polygon shape.

[0092] Alternatively and / or additionally, Example 15 includes Example 14, wherein the counter-rotating hubs of the wheel are used to push the first group of struts and pull the second group of struts.

[0093] Alternatively and / or additionally, Example 16 includes one or more of Examples 14 to 15, wherein the first of the counter-rotating hubs pushes the first group of struts and pulls at least some of the struts from the second group of struts.

[0094] Example 17 may comprise a vehicle including: a body; and at least two wheels coupled to the body, each wheel comprising: at least two hubs along a rotational axis, each hub being rotatable independently about the axis; a shape-adaptable rim; and a plurality of rigid struts extending outwardly from the hub to the rim, each strut having a first end pivotally connected to one of the hubs and a second end pivotally connected to the rim.

[0095] Alternatively and / or additionally, Example 18 includes Example 17, wherein each wheel further comprises a torsion spring coupled between the hubs.

[0096] Alternatively and / or additionally, Example 19 includes one or more of Examples 17 to 18, wherein each wheel further comprises an axle defining the rotational axis, the hubs being mounted for rotation about the axle.

[0097] Alternatively and / or additionally, Example 20 includes one or more of Examples 17 to 19, wherein the rim of each wheel is flexible and continuous.

[0098] Alternatively and / or additionally, Example 21 includes one or more of Examples 17 to 20, wherein the rim of each wheel comprises a plurality of arcuate segments, wherein the ends of adjacent segments are hinged at pivot points, and wherein the second ends of the struts are also hinged at the pivot points.

[0099] Alternatively and / or additionally, Example 22 includes one or more of Examples 17 to 21, further comprising a suspension system for supporting the body, wherein the at least two wheels are coupled to the suspension system.

[0100] Alternatively and / or additionally, Example 23 includes one or more of Examples 17 to 22, wherein the at least two hubs comprise a first hub and a second hub; and wherein the vehicle further comprises a shock absorber coupled between the arms of the first hub and the second hub.

[0101] The descriptions of the various embodiments herein have been presented for illustrative purposes and are not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The terms used herein are chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable those of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A wheel having a rotational axis, the wheel comprising: at least two hubs, along the rotational axis, each hub being rotatable independently about the axis; a rim of adaptable shape; and a plurality of rigid struts extending outwardly from the hubs to the rim, each strut having a first end pivotally connected to one of the hubs and a second end pivotally connected to the rim.

2. The wheel according to claim 1, wherein the rotational axis is perpendicular to a rotational plane, and wherein the struts pivot along an axis that is also perpendicular to the rotational plane.

3. The wheel according to claim 1, wherein the hubs and struts are configured to cause reverse rotation of the hubs when an operating load is applied to the hubs.

4. The wheel according to claim 3, wherein the struts are attached to the hubs to form at least one eccentric pivot on each hub to cause the reverse rotation.

5. The wheel according to claim 3, wherein the reverse rotation causes a first group of the struts to push the rim to form nodes, and a second group of the struts to pull the rim to form sides, thereby causing the rim to conform to a rounded polygon shape.

6. The wheel according to claim 5, wherein the rounded polygon shape includes rolling flat spots during rotation of the rim.

7. The wheel according to claim 5, wherein the wheel has a three-node design.

8. The wheel according to claim 3, wherein in the absence of an operating load on the wheel, the rim has a circular shape, and each strut is substantially perpendicular to a line radially extending from the rotational axis through the pivot axis at the first end.

9. The wheel according to claim 1, further comprising a member for resisting relative rotation of the hubs.

10. The wheel according to claim 1, further comprising a torsion spring coupled between the hubs.

11. The wheel according to claim 1, wherein the at least two hubs include a first hub and a second hub; wherein a first group of the struts is pivotally connected to the first hub, and a second group of the struts is pivotally connected to the second hub; wherein reverse rotation of the first hub and the second hub causes the first group of struts to push against the rim to form nodes, and the second group of struts to pull the rim to form a circular wall; and wherein the first group of the struts includes one strut for each of the nodes.

12. The wheel according to claim 1, wherein the rim is flexible and continuous.

13. The wheel according to claim 1, wherein the rim includes a plurality of arcuate segments, wherein the ends of adjacent segments are hinged at pivot points, and wherein the second ends of the struts are also hinged at the pivot points.

14. A method for a wheel having a rim of adaptable shape and a plurality of struts pivotally attached to the rim, the method comprising: pushing a first group of the struts to form nodes of a rounded polygon shape; and pulling a second group of the struts to form sides of the rounded polygon shape.

15. The method according to claim 14, wherein the reverse-rotating hubs of the wheels are configured to push the first group of struts and pull the second group of struts.

16. The method according to claim 15, wherein a first one of the reverse-rotating hubs pushes the first group of struts and pulls at least some of the struts from the second group of struts.

17. A vehicle, which comprises: a body; and at least two wheels coupled to the body, each wheel comprising: at least two hubs along a rotational axis, each hub being rotatable independently about the axis; a shape-adaptable rim; and a plurality of rigid struts extending outwardly from the hub to the rim, each strut having a first end pivotally connected to one of the hubs and a second end pivotally connected to the rim.

18. The vehicle according to claim 17, wherein each wheel further comprises a torsion spring coupled between the hubs.

19. The vehicle according to claim 17, wherein each wheel further comprises an axle defining the rotational axis, the hubs being mounted for rotation about the axle.

20. The vehicle according to claim 17, wherein the rim of each wheel is flexible and continuous.

21. The vehicle according to claim 17, wherein the rim of each wheel comprises a plurality of arcuate segments, wherein the ends of adjacent segments are hinged at a pivot point, and wherein the second ends of the struts are also hinged at the pivot point.

22. The vehicle according to claim 17, further comprising a suspension system for supporting the body, wherein the at least two wheels are coupled to the suspension system.

23. The vehicle according to claim 22, wherein the at least two hubs comprise a first hub and a second hub; and wherein the vehicle further comprises a shock absorber coupled between the arms of the first hub and the second hub.

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