Flexible blade fan

摘要

A cooling fan for a powered vehicle, adapted for automotive use, and having a hub and a plurality of radial fan blades made integral therewith of synthetic resin material, the fan blade being characterized by provision of a transverse cross section through a limited area of the blade. The transverse cross section is contoured under a condition in which rate of continuous thickness change between a middle point and the leading edge in the transverse cross section is regulated relative to a thickness of the middle point so that the ratio of the thickness of the leading edge divided by the thickness of the middle point falls in a range of from 1.0 to 1.5 while another rate of continuous thickness change between the middle point and the trailing edge in the transverse cross section is similarly regulated so that another similar ratio falls in a range of from 0.7 to 1.2. The middle point is locationally determined by a distance from the leading edge to the middle point.