Wheel with dual density

Abstract

A wheel is provided for coupling to a bearing case at an outer cylindrical surface and a lateral annular surface of the bearing case. The wheel includes an inner wheel portion with an annular body defining a central hole with an inner cylindrical surface and a lateral annular surface for engaging the bearing case. The inner wheel portion may substantially comprise a thermoset, polyurethane material having a density and have a surface exhibiting a hardness. The wheel also may include an outer wheel portion bonded to the inner wheel portion. The outer wheel portion may be substantially comprised of the same thermoset, polyurethane material as the inner wheel portion. The outer wheel surface may exhibit a hardness substantially the same as that of the inner wheel surface. The inner wheel material may have a lesser density than that of the outer wheel material. The lesser density of the inner wheel portion may be provided by gas bubbles included in the material of the inner wheel portion, which bubbles may be provided by hollow plastic spheres.

Dependencies are inferred from the claim text.