Plastic fans having improved fan ring weld line strength

A method for improving outer ring strength of a fan used in a fan drive system, the fan having a plurality of fan blades coupled between the outer ring and an inner ring, the method comprising:

• determining a location of a weld line in the outer ring of the molded fan between each adjacent pair of the plurality of fan blades, said weld line corresponding to a weakest portion of the outer ring between the adjacent pair of the plurality of fan blades;
• forming a mold having an interior, said interior corresponding to the size and shape of the molded fan, said mold having a plurality of gates located around the inner ring, one of the plurality of gates closely coupled to the inner ring at a position corresponding to one of the plurality of fan blades, wherein said mold has an increased thickness corresponding to each of said locations within a mold;
• introducing a quantity of a molten raw material simultaneously through each of the plurality of gates and within said interior at a desired temperature and pressure;
• cooling said quantity of molten raw material within said mold to form the fan;
• and
• removing the fan from said mold.

A method for improving outer ring strength of a fan used in a fan drive system, the fan having a plurality of fan blades coupled between the outer ring and an inner ring, the method comprising:

• determining a location of a weld line in the outer ring of the molded fan between each adjacent pair of the plurality of fan blades, said weld line corresponding to a weakest portion of the outer ring between the adjacent pair of the plurality of fan blades, said weld line defining a fairly planar region of said outer ring that is nearly perpendicular to a tangential alignment of said outer ring;
• forming a mold having an interior, said interior corresponding to the size and shape of the molded fan, said mold having a plurality of gates located around the inner ring, one of the plurality of gates closely coupled to the inner ring at a position corresponding to one of the plurality of fan blades, wherein said mold has at least one appendage attached to the outer ring corresponding to each of said locations within a mold;
• introducing a quantity of a molten raw material simultaneously through each of the plurality of gates and within said interior at a desired temperature and pressure;
• cooling said quantity of molten raw material within said mold to form the fan;
• and
• removing the fan from said mold.

A molded ring fan having improved outer ring strength, the molded ring fan comprising:

• an inner ring;
• a plurality of blades disposed circumferentially about said inner ring, each of said plurality of blades having a root and a blade tip;
• and
• an outer ring disposed circumferentially about said plurality of blades, wherein each of said roots is flowingly coupled with said inner ring and wherein each of said blade tips is flowingly coupled to said outer ring, said outer ring having a thickened middle region between each adjacent pair of said plurality of blades.

A molded ring fan having improved outer ring strength, the molded ring fan comprising:

• an inner ring;
• a plurality of blades disposed circumferentially about said inner ring, each of said plurality of blades having a root and a blade tip;
• an outer ring disposed circumferentially about said plurality of blades, wherein each of said roots is flowingly coupled with said inner ring and wherein each of said blade tips is flowingly coupled to said outer ring;
• and
• at least one removable appendage coupled along said outer ring, one of said at least one removable appendages coupled approximately midway between an adjacent pair of said plurality of blades.