Wheel assembly with outer hub having polygonal shape
A wheel assembly includes a rim, an inner hub concentric with the rim, and an outer hub concentric with the rim and the inner hub. The outer hub is between the rim and the inner hub. The wheel assembly includes a first set of spokes spaced circumferentially about the inner hub between the inner hub and the outer hub. The first set of spokes are elongated radially from the inner hub and having a sinusoidal shape. The wheel assembly includes a second set of spokes spaced circumferentially about the outer hub between the outer hub and the rim. The second set of spokes are elongated radially from the outer hub and having a sinusoidal shape. The second set of spokes are aligned with the first set of spokes circumferentially about the outer hub.
1 . A wheel assembly comprising:
a rim;
an inner hub concentric with the rim;
an outer hub concentric with the rim and the inner hub, the outer hub being between the rim and the inner hub;
a first set of spokes between the inner hub and the outer hub, the spokes of the first set of spokes being elongated radially from the inner hub and having a sinusoidal shape;
a second set of spokes between the outer hub and the rim, the spokes of the second set of spokes being spaced from each other circumferentially about the outer hub and elongated from the outer hub to the rim and having a sinusoidal shape; and
the outer hub having a polygonal shape having sides and vertices;
at each vertex, a spoke of the first set of spokes being aligned circumferentially about the outer hub with a spoke of the second set of spokes.
2 . The wheel assembly of claim 1 , wherein each spoke of the first set of spokes is fixed to the inner hub and the outer hub and each spoke of the second set of spokes is fixed to the outer hub and the rim.
3 . The wheel assembly of claim 1 , wherein the outer hub is spaced from the inner hub by the first set of spokes and the outer hub is spaced from the rim by the second set of spokes.
4 . The wheel assembly of claim 1 , wherein:
the rim, the first set of spokes, the second set of spokes, and the outer hub are rotatable about a rotational axis of the inner hub; and
the rim, the first set of spokes, the second set of spokes, and the outer hub are deformable relative to the inner hub.
5 . The wheel assembly of claim 1 , wherein the outer hub has four vertices circumferentially spaced by 90 degrees.
6 . The wheel assembly of claim 5 , wherein the outer hub and the spokes of the first set of spokes and the second set of spokes are designed so that, when the rim deforms at a deformation area, the spoke of the second set of spokes nearest the deformation area is compressed between the rim and the outer hub and the two spokes of the second set of spokes at the vertices spaced at 90 degrees from the deformation area are in tension between the rim and the outer hub.
7 . The wheel assembly of claim 6 , wherein the spoke of the first set of spokes nearest the deformation area is compressed between the outer hub and the inner hub and the two spokes of the first set of spokes at the vertices spaced at 90 degrees from the deformation area are in tension between the outer hub and the inner hub.
8 . The wheel assembly of claim 1 , wherein the outer hub is octagonal with eight vertices.
9 . The wheel assembly of claim 8 , wherein:
the rim defines a vertical axis and a horizontal axis perpendicular to each other and perpendicular to a rotational axis of the inner hub; and
the rim, the first set of spokes, the second set of spokes, and the outer hub are designed so that, when a force is applied to the rim along the horizontal axis:
the first set of spokes and the second set of spokes are in compression when one of the spokes extends along the horizontal axis and when an angle between the spoke and the horizontal axis is less than an angle between the spoke and the vertical axis; and
the first set of spokes and the second set of spokes are in tension when one of the spokes extends along the vertical axis and when an angle between the spoke and the vertical axis is less than an angle between the spoke and the horizontal axis.
10 . The wheel assembly of claim 1 , wherein each spoke of the second set of spokes meets one of the spokes of the first set of spokes, respectively, at the outer hub.
11 . A vehicle comprising:
a vehicle frame; and
a wheel supported by the vehicle frame, the wheel being rotatable relative to the vehicle frame;
the wheel having a rim;
the wheel having an inner hub concentric with the rim;
the wheel having an outer hub concentric with the rim and the inner hub, the outer hub being between the rim and the inner hub;
the wheel having a first set of spokes between the inner hub and the outer hub, the spokes of the first set of spokes being elongated radially from the inner hub and having a sinusoidal shape;
the wheel having a second set of spokes between the outer hub and the rim, the spokes of the second set of spokes being spaced from each other circumferentially about the outer hub and elongated from the outer hub to the rim and having a sinusoidal shape;
the outer hub having a polygonal shape having sides and vertices; and
at each vertex, a spoke of the first set of spokes being aligned circumferentially about the outer hub with a spoke of the second set of spokes.
12 . The vehicle of claim 11 , wherein each spoke of the first set of spokes is fixed to the inner hub and the outer hub and each spoke of the second set of spokes is fixed to the outer hub and the rim.
13 . The vehicle of claim 11 , wherein the outer hub is spaced from the inner hub by the first set of spokes and the outer hub is spaced from the rim by the second set of spokes.
14 . The vehicle of claim 11 , wherein the outer hub has four vertices circumferentially spaced by 90 degrees.
15 . The vehicle of claim 14 , wherein the outer hub and the spokes of the first set of spokes and the second set of spokes are designed so that, when the rim deforms at a deformation area, the spoke of the second set of spokes nearest the deformation area is compressed between the rim and the outer hub and the two spokes of the second set of spokes at the vertices spaced at 90 degrees from the deformation area are in tension between the rim and the outer hub.
16 . The vehicle of claim 15 , wherein the spoke of the first set of spokes nearest the deformation area is compressed between the outer hub and the inner hub and the two spokes of the first set of spokes at the vertices spaced at 90 degrees from the deformation area are in tension between the outer hub and the inner hub.
17 . The vehicle of claim 11 , wherein the outer hub is octagonal with eight vertices.
18 . The vehicle of claim 17 , wherein:
the rim defines a vertical axis and a horizontal axis perpendicular to each other and perpendicular to a rotational axis of the inner hub; and
the rim, the first set of spokes, the second set of spokes, and the outer hub are designed so that, when a force is applied to the rim along the horizontal axis:
the first set of spokes and the second set of spokes are in compression when one of the spokes extends along the horizontal axis and when an angle between the spoke and the horizontal axis is less than an angle between the spoke and the vertical axis; and
the first set of spokes and the second set of spokes are in tension when one of the spokes extends along the vertical axis and when an angle between the spoke and the vertical axis is less than an angle between the spoke and the horizontal axis.
19 . The vehicle of claim 1 , wherein the polygonal shape of the outer hub is a regular polygon.
20 . The vehicle of claim 11 , wherein the polygonal shape of the outer hub is a regular polygon.