| 摘要 |
<p>A two-bladed propeller fan for wind machines, having a teetering hub for mounting in spaced relationship on a driving shaft, a pair of tangs 180 DEG apart extending outwardly of the hub, each tang having opposed parallel flat surfaces at an acute angle normal to the axis about which the fan revolves, a fan blade extending diametrically outwardly from each respective tang, laminated splice plates securing each blade to a respective tang, said splice plates extending adjacent both sides of said tang parallel surfaces and adjacent both sides of said blades, the outer ends of the tangs and the inner ends of the respective blades being in abutment, said splice plates being in layers of different lengths, the longest of the splice plates on each side being adjacent said tangs and blades, and each plate layered outwardly of the longest plate being successivey shorter so as to form a series of descending steps at their ends diametrically outwardly from the tangs and on the blades; the splice plates being arranged to distribute the stress load on the blades over an extended area, to avoid stress concentrations, to apply gradual bending and loading of the blades adjacent the plates, and to permit flexing of the plates and blades over a substantial portion of said area.</p> |
