Patent 9366332 was granted and assigned to Sumitomo Heavy Industries on June, 2016 by the United States Patent and Trademark Office.
A power transmission device includes a casing, a first shaft, and a second shaft, wherein the first shaft has a protruding portion which protrudes from the casing, a fan is provided at the protruding portion, a fan cover configured to cover the fan has an extending portion which extends toward a bearing supporting portion of the second shaft along a side surface of the casing, and the extending portion is inclined so as to approach the side surface of the casing toward the bearing supporting portion side from the fan side.