Fan shroud structure reinforcement to reduce or eliminate warping and distortion

A fan shroud structure 10 is constructed and arranged to carry a fan and motor. The fan shroud structure includes a base 12 and an annular rim 24 extending from the base. The rim defines a generally central opening 26 sized to accommodate blades of a fan. Motor mounting structure 28 is coupled with the rim 24 and is disposed generally adjacent to the central opening 26 . The motor mounting structure 28 is constructed and arranged to support a motor for driving a fan. The fan shroud structure 10 includes a first pair of opposing sides 14, 16 and a second pair of opposing sides 17, 18 coupled to the base to form a box-like configuration defining a perimeter of the fan shroud structure raised with respect to the base such that the sides are discontinuous with respect to the base 12 to shift resonance of the shroud structure.