Fan assemblies and method of making same

A fan assembly comprising an annular hub which fits over a motor axle to rotate therewith, a spider fixed to said hub, said spider having a plurality of arms, and a plurality of fan blades fixed to said spider arms having a root section and an ear section;

• said blade being in the form of an arc defining a chord which decreases along said root section and increases along said ear section, the arc being defined by arcs of two circles, one arc defining 1/3 of the chord length, the other arc defining 1/2 the chord length;
• said blade having a blade pitch angle of between 22.degree. -50.degree. and a depitch angle which decreases from the root to the top of said ear section and camber which is kept constant as a percent of said chord.

An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear at a rate of about 0.15"/inch of blade length and then increasing from said ear to said tip by about 0.177"/inch of blade length.

An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to aid ear and then increasing from said ear to said tip;

• said airfoil shape being defined by a first arc, which defines said leading edge, and a second arc which defines said trailing edge;
• said fan blade having a constant camber ratio.

An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edge and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear and then increasing from said ear to said tip;

• said blade having a pitch which decreases along the length thereof at a rate of about 1.5.degree./inch to 3.degree./inch.

An airfoil shaped fan blade having a root, a tip, an ear between said root and said tip, and a leading edged and a trailing edge, the distance between said edges defining a chord, said chord decreasing from said root to said ear and then increasing from said ear to said tip;

• said blade having a pitch which decreases along the length thereof;
• said blades have a pitch angle of between 25.degree. -40.degree. ;