Patent ID: 9322407
Filing Date: 2016-04-26
CPC Classification: F04D

Claim Text:
1. A contra-rotating fan system for evaporative cooling equipment comprising: a first axial fan; a second axial fan arranged coaxially with the first axial fan; and a transmission, the transmission comprising (a) a lower drive unit having a first drive assembly with a first predetermined drive ratio and (b) an upper drive unit having a second drive assembly with a second predetermined drive ratio, wherein the first drive assembly comprises a center pinwheel driver, an outer pinwheel receiver, and a plurality of intermediate pinwheels, wherein the lower drive unit is operatively coupled to a motor, the lower drive unit being configured to (i) drive the upper drive unit, and (ii) rotate the first axial fan at a first speed of rotation in a first direction, wherein the upper drive unit is configured to rotate the second axial fan at a second speed of rotation in a second direction, wherein the direction of rotation of the first direction is opposite to the direction of rotation of the second direction.