| 摘要 |
A ventilation fan arranged to reduce vibrations includes an impeller rotating around a center axis, a motor portion arranged to rotate the impeller, a motor supporting portion arranged to support the motor portion, and a housing arranged to accommodate the impeller and the motor portion. The motor supporting portion includes a substantially disk-shaped base portion, and a substantially cylindrical bearing holding portion axially extending with the center axis as the center. At least the base portion is made from resin. On the surface of the base portion, a plurality of recessed portions which are axially recessed are arranged in the form of a net, a staggered pitch, a grid, or a honeycomb. A flat portion of the base portion excluding the recessed portions does not have a continuous region extending in a straight line radially from the center of the base portion. |
