Fan blade structure

Abstract

A fan blade structure includes a case, a rotor and a fan blade unit. The case has a top portion and a sidewall portion connected to an outer periphery of the top portion to thereby define a receiving space therein. The rotor is mounted in the receiving space to contact with an inner wall surface of the sidewall portion in a tight-fit relation. The fan blade unit is formed by stamping a metal material, and includes an annular top face bearing on the top portion of the case, and a plurality of blades equally spaced along the annular top face. The annular top face defines a large-area central opening, which effectively reduces an overall weight of the fan blade unit and thereby lowers the load of the rotor and allows a fan motor in operation to reach its high limit of rotary speed and enable an upgraded fan rotating speed.

1 . A fan blade structure, comprising:
 a case having a top portion and a sidewall portion, the sidewall portion being connected at one end to an outer periphery of the top portion to thereby define a receiving space between the top portion and the sidewall portion;   a rotor being mounted in the receiving space in the case to contact with an inner wall surface of the sidewall portion in a tight-fit relation; and   a fan blade unit including an annular top face for bearing on the top portion of the case, and a plurality of blades extended from an outer periphery of the annular top face; and the annular top face defining a large-area central opening, from which a large part of the top portion of the case is exposed.   
     
     
         2 . The fan blade structure as claimed in  claim 1 , wherein the fan blade unit is fixedly held to the case by welding the annular top face to the top portion of the case. 
     
     
         3 . The fan blade structure as claimed in  claim 1 , wherein the fan blade unit is formed by stamping to directly form the central opening on the annular top face while stamping, so as to effectively reduce an overall weight of the fan blade unit. 
     
     
         4 . The fan blade structure as claimed in  claim 3 , wherein the fan blade unit is formed by stamping a metal material. 
     
     
         5 . The fan blade structure as claimed in  claim 1 , wherein the fan blade unit further includes at least one extension section; the extension section having a proximal end integrally connected to the outer periphery of the annular top face and a distal end integrally connected to one side of the blades. 
     
     
         6 . The fan blade structure as claimed in  claim 5 , wherein each of the blades has a front edge, a rear edge, and an air-guiding face; and the air-guiding face being located between the front edge and the rear edge with one side connected to the extension section. 
     
     
         7 . The fan blade structure as claimed in  claim 6 , wherein the front edge of any of the blades is spaced from and located higher than the rear edge of an adjacent preceding blade by a fixed distance.