A powered retraction system for a wheel

A powered retraction system for a wheel rotatable about a wheel axle, the retraction system comprising an actuation system to raise the wheel to a stowed position and to lower the wheel to a steer position, wherein the actuation system comprises:

• a motor;
• a rotational drive element rotatable in a first direction and a second direction by the motor;
• a rotatable torsion controller rotatable about a torsion controller axis;
• a link rotatably connected to the rotational drive element and to the torsion controller to transfer rotational movement of the drive element to the torsion controller;
• and
• a torsion element comprising opposing first and second ends and comprising a major axis extending substantially parallel to the wheel axle, the torsion element being held under tension;
• and a swing arm rotatable about a swing arm axis by the torsion controller, wherein the swing arm is operably connected to the wheel axle, distanced from the swing arm axis, such that rotating the swing arm about its rotational axis raises or lowers the wheel,
• wherein the first end of the torsion element is fixedly engaged with the rotatable torsion controller and the second end of the torsion element is fixedly engaged with the swing arm,
• wherein rotation of the torsion controller in a first direction rotates the first end of the torsion element and provides torsion applied by the torsion element to the swing arm to urge the swing arm, and in turn the wheel, downwards against a surface;
• and
• wherein rotation of the torsion controller in a second direction rotates the first end of the torsion element to decrease torsion applied by the torsion element to the swing arm and reduces downward pressure on the swing arm and therefore on the wheel to raise the wheel to the stowed position.