A movable robot (1) includes a main body unit (2), and at least three wheel units (4a,4b,4c) connected with the main body unit (2). The wheel units (4a,4b,4c) have respective contact portions (6a,6b,6c) for contact with a floor surface (8). The contact portions (6a,6b,6c) are rotatable about respective axes (3a,3b,3c). The main body unit (2) moves along the floor surface (8) as the contact portions (6a,6b,6c) rotate. Lines projected onto the floor surface and originating from the axes of rotation (3a,3b,3c) of the contact portions (6a,6b,6c) are spaced at substantially equal angular intervals θ_ab,θ_bc,θ_ca). At most two of the axes (3a,3b,3c) are on a common plane. Each of the wheel units (4a,4b,4c) includes a motor base, a rotation drive motor (10a,10b,10c) supported on the motor base, a casing being rotatable relative to the motor base about related one of the axes and having related one of the contact portions, and a device for transmitting a rotational force generated by the rotation drive motor to the casing.

There is provided, in a preferred embodiment, a transportation vehicle for transporting an individual over ground having a surface that may be irregular. This embodiment has a support for supporting the subject. A. ground-contacting module, movably attached to the support, serves to suspend the subject in the support over the surface. The orientation of the ground-contacting module defines fore-aft and lateral planes intersecting one another at a vertical. The support and the ground-contacting module are components of an assembly. A motorized drive, mounted to the assembly and coupled to the ground-contacting module, causes locomotion of the assembly and the subject therewith over the surface. Finally, the embodiment has a control loop, in which the motorized drive is included, for dynamically enhancing stability in the fore-aft plane by operation of the motorized drive in connection with the ground-contacting module. Included in the control loop is a directional control, letting the vehicle move, lean and turn in response to an indication of the subject, e.g. that of leaning the vehicle. The ground contacting module may be realized as a pair of ground-contacting members, laterally disposed with respect to one another. The ground-contacting members may be wheels, a duster of wheels, or includes rotatably mounted arcuate element pairs.

La roue (3) comporte un voile annulaire (3a) s'engageant dans une saignée verticale ouverte (4) ménagée de manière déportée vers l'extérieur à la base du support (2) et dont le fond arrondi (4a) constitue butée contre laquelle porte une partie de l'aréte intérieure du voile (3a) soit au repos, soit lorsque la roue tourne.

A drum-shaped hub (10) is attached to an end of an axle A of a tractor, and an outer ring (17) which retains a tire is screwed onto a drum portion of the hub. The outer ring (17) is located at a predetermined position on the hub drum portion and is then secured by fixing devices (10a, 15, 19). If the axle A of the tractor is rotated under the state in which the fixing devices are removed and the outer ring (17) is screwed onto the hub drum portion, the position of the outer ring (17) along the hub drum portion changes, thereby enabling an easy adjustment of the track width.