Dynamically balanced molded blade assemblies for blowers and fans

Abstract

Dynamically balanced molded blade assemblies may be formed. A face plate of a dynamically balanced molded blade assembly may have one or more openings and/or one or more protrusions so that the blade assembly is within acceptable balance tolerance when rotated by a motor shaft of a fluid moving device.

1 . A molded blade assembly, comprising:
 a plurality of blades;   a face plate coupled to the plurality of blades, wherein the face plate comprises:
 a hub with a shaft bore configured to couple the blade assembly to a shaft of a motor; and 
 balancing means configured to dynamically balance the blade assembly within acceptable balance tolerance when the blade assembly is rotated by the shaft of the motor during use. 
   
   
   
       2 . The molded blade assembly of  claim 1 , wherein the balancing means comprises one or more openings formed in the face plate. 
   
   
       3 . The molded blade assembly of  claim 1 , wherein the balancing means comprises a plurality of openings formed in the face plate, and wherein at least one of the openings comprises an opening completely through the face plate. 
   
   
       4 . The molded blade assembly of  claim 1 , wherein the balancing means comprises a plurality of openings formed in the face plate, and wherein the openings are evenly spaced angularly about a center of the face plate or irregularly spaced angularly about the center of the face plate. 
   
   
       5 . The molded blade assembly of  claim 1 , wherein the balancing means comprises a plurality of openings formed in the face plate, and wherein at least one of the openings has a different size than at least one other opening. 
   
   
       6 . The molded blade assembly of  claim 1 , wherein the balancing means comprises at least one blind opening formed in the face plate. 
   
   
       7 . The molded blade assembly of  claim 1 , wherein the balancing means comprises one or more protrusions extending from the face plate. 
   
   
       8 . The molded blade assembly of  claim 1 , wherein the balancing means comprises at least one protrusion extending from the face plate, and at least one opening formed in the face plate. 
   
   
       9 . A fluid moving device, comprising:
 a motor having a shaft;   a molded blade assembly coupled to the shaft, wherein the blade assembly comprises a hub with a shaft opening, a face plate, and a plurality of blades; and   wherein the face plate includes balancing means for dynamically balancing the blade assembly within acceptable balance tolerance when the blade assembly is rotated at operating speed by the shaft.   
   
   
       10 . The fluid moving device of  claim 9 , wherein the fluid moving device is a blower. 
   
   
       11 . The fluid moving device of  claim 9 , wherein the fluid moving device is a fan. 
   
   
       12 . The fluid moving device of  claim 9 , wherein the balancing means comprises one or more openings formed in the face plate. 
   
   
       13 . The fluid moving device of  claim 9 , wherein the balancing means comprises a plurality of openings formed in the face plate, and wherein at least one of the openings comprises an opening completely through the face plate. 
   
   
       14 . The fluid moving device of  claim 9 , wherein the balancing means comprises a plurality of openings formed in the face plate, and wherein the openings are evenly spaced angularly about a center of the face plate or irregularly spaced angularly about the center of the face plate. 
   
   
       15 . The fluid moving device of  claim 9 , wherein the balancing means comprises a plurality of openings formed in the face plate, and wherein at least one of the openings has a different size than at least one other opening. 
   
   
       16 . The fluid moving device of  claim 9 , wherein the balancing means comprises at least one blind opening formed in the face plate. 
   
   
       17 . The fluid moving device of  claim 9 , wherein the balancing means comprises one or more protrusions extending from the face plate. 
   
   
       18 . The fluid moving device of  claim 9 , wherein the balancing means comprises at least one protrusion extending from the face plate, and at least one opening formed in the face plate. 
   
   
       19 . A method of producing dynamically balanced molded blade assemblies, comprising:
 forming a first blade assembly using a mold;   coupling the first blade assembly to a test machine;   operating the test machine to determine the balance characteristics of the first blade assembly at a working rotational speed;   assessing a location of one or more balancing means to be incorporated in a face plate of the first blade assembly to result in a dynamically balanced first blade assembly; and   adjusting the mold to form the balancing means in the face plate of a blade assembly produced by the mold; and   using the mold to form one or more dynamically balanced blade assemblies.   
   
   
       20 . The method of  claim 19 , wherein the balancing means comprises at least one opening formed in a face plate of a blade assembly produced by the mold. 
   
   
       21 . The method of  claim 19 , wherein the balancing means comprises at least one protrusion formed as part of the face plate of a blade assembly produced by the mold.