Fan impeller structure of centrifugal fan

Abstract

A fan impeller structure of centrifugal fan includes a hub, a first blade body set and a second blade body set. The hub has an extension section having a first side and a second side. The first blade body set is disposed on the first side, while the second blade body set is disposed on the second side. The first blade body set defines multiple first air inlets and multiple first air outlets. The second blade body set defines multiple second air inlets and multiple second air outlets. The first air outlets of the first blade body set or the second air outlets of the second blade body set are selectively arranged at unequal intervals so as to effectively reduce noise.

What is claimed is: 
     
         1 . A fan impeller structure of centrifugal fan, comprising:
 a hub having an extension section, the extension section having a first side and a second side;   a first blade body set disposed on the first side, the first blade body set including multiple first blade bodies, the first blade bodies defining therebetween multiple first air inlets and multiple first air outlets, the first air outlets being arranged at unequal intervals; and   a second blade body set disposed on the second side, the second blade body set including multiple second blade bodies, the second blade bodies defining therebetween multiple second air inlets and multiple second air outlets.   
     
     
         2 . The fan impeller structure of centrifugal fan as claimed in  claim 1 , wherein the first blade body set extends from the first side of the extension section in a direction away from the hub, each first blade body having a first end and a second end, the first air inlet being defined between the first ends of each two adjacent first blade bodies, the first air outlet being defined between the second ends of each two adjacent first blade bodies, the second blade body set extending from the second side of the extension section in a direction away from the hub, each second blade body having a third end and a fourth end, the second air inlet being defined between the third ends of each two adjacent second blade bodies, the second air outlet being defined between the fourth ends of each two adjacent second blade bodies. 
     
     
         3 . The fan impeller structure of centrifugal fan as claimed in  claim 2 , wherein the first ends together define a first pitch circle, a tangent of the first pitch circle at the first end being defined as a first tangent, the first blade body having a first blade body central line, a tangent of the first blade body central line at the first end being defined as a second tangent, the second tangent intersecting the first tangent to contain a first air incoming angle, the second ends together defining a second pitch circle, a tangent of the second pitch circle at the second end being defined as a third tangent, a tangent of the first blade body central line at the second end being defined as a fourth tangent, the third tangent and the fourth tangent containing a first air outgoing angle, the third ends together defining a third pitch circle, a tangent of the third pitch circle at the third end being defined as a fifth tangent, the second blade body having a second blade body central line, a tangent of the second blade body central line at the third end being defined as a sixth tangent, the fifth tangent intersecting the sixth tangent to contain a second air incoming angle, the fourth ends together defining a fourth pitch circle, a tangent of the fourth pitch circle at the fourth end being defined as a seventh tangent, a tangent of the second blade body central line at the fourth end being defined as an eighth tangent, the seventh tangent and the eighth tangent containing a second air outgoing angle. 
     
     
         4 . The fan impeller structure of centrifugal fan as claimed in  claim 3 , wherein the first air incoming angle is larger than or equal to the second air incoming angle. 
     
     
         5 . The fan impeller structure of centrifugal fan as claimed in  claim 3 , wherein the first air outgoing angle is larger than or equal to the second air outgoing angle. 
     
     
         6 . The fan impeller structure of centrifugal fan as claimed in  claim 3 , wherein the first air incoming angle is smaller than or equal to the second air incoming angle. 
     
     
         7 . The fan impeller structure of centrifugal fan as claimed in  claim 3 , wherein the first air outgoing angle is smaller than or equal to the second air outgoing angle. 
     
     
         8 . The fan impeller structure of centrifugal fan as claimed in  claim 2 , wherein the second end has a height larger than that of the fourth end. 
     
     
         9 . The fan impeller structure of centrifugal fan as claimed in  claim 2 , wherein the fourth end has a height larger than that of the second end. 
     
     
         10 . The fan impeller structure of centrifugal fan as claimed in  claim 1 , wherein the first blade body has a length larger than that of the second blade body. 
     
     
         11 . The fan impeller structure of centrifugal fan as claimed in  claim 1 , wherein the second blade body has a length larger than that of the first blade body. 
     
     
         12 . The fan impeller structure of centrifugal fan as claimed in  claim 2 , wherein the first end is aligned with the third end. 
     
     
         13 . The fan impeller structure of centrifugal fan as claimed in  claim 3 , wherein the first end is not aligned with the third end and the first and second air inlets are not aligned with each other. 
     
     
         14 . The fan impeller structure of centrifugal fan as claimed in  claim 1 , wherein the number of the first blade bodies is more than the number of the second blade bodies. 
     
     
         15 . The fan impeller structure of centrifugal fan as claimed in  claim 1 , wherein the number of the second blade bodies is more than the number of the first blade bodies. 
     
     
         16 . The fan impeller structure of centrifugal fan as claimed in  claim 1 , wherein the second blade bodies of the second blade body set are arranged at equal intervals or unequal intervals. 
     
     
         17 . A fan impeller structure of centrifugal fan, comprising:
 a hub having an extension section, the extension section having a first side and a second side;   a first blade body set disposed on the first side, the first blade body set including multiple first blade bodies, the first blade bodies defining therebetween multiple first air inlets and multiple first air outlets, the first air outlets being arranged at equal intervals; and   a second blade body set disposed on the second side, the second blade body set including multiple second blade bodies, the second blade bodies defining therebetween multiple second air inlets and multiple second air outlets, the second air outlets being arranged at unequal intervals.   
     
     
         18 . The fan impeller structure of centrifugal fan as claimed in  claim 17 , wherein the first blade body set extends from the first side of the extension section in a direction away from the hub, each first blade body having a first end and a second end, the first air inlet being defined between the first ends of each two adjacent first blade bodies, the first air outlet being defined between the second ends of each two adjacent first blade bodies, the second blade body set extending from the second side of the extension section in a direction away from the hub, each second blade body having a third end and a fourth end, the second air inlet being defined between the third ends of each two adjacent second blade bodies, the second air outlet being defined between the fourth ends of each two adjacent second blade bodies. 
     
     
         19 . The fan impeller structure of centrifugal fan as claimed in  claim 18 , wherein the first ends together define a first pitch circle, a tangent of the first pitch circle at the first end being defined as a first tangent, the first blade body having a first blade body central line, a tangent of the first blade body central line at the first end being defined as a second tangent, the second tangent intersecting the first tangent to contain a first air incoming angle, the second ends together defining a second pitch circle, a tangent of the second pitch circle at the second end being defined as a third tangent, a tangent of the first blade body central line at the second end being defined as a fourth tangent, the third tangent and the fourth tangent containing a first air outgoing angle, the third ends together defining a third pitch circle, a tangent of the third pitch circle at the third end being defined as a fifth tangent, the second blade body having a second blade body central line, a tangent of the second blade body central line at the third end being defined as a sixth tangent, the fifth tangent intersecting the sixth tangent to contain a second air incoming angle, the fourth ends together defining a fourth pitch circle, a tangent of the fourth pitch circle at the fourth end being defined as a seventh tangent, a tangent of the second blade body central line at the fourth end being defined as an eighth tangent, the seventh tangent and the eighth tangent containing a second air outgoing angle. 
     
     
         20 . The fan impeller structure of centrifugal fan as claimed in  claim 19 , wherein the first air incoming angle is larger than or equal to the second air incoming angle. 
     
     
         21 . The fan impeller structure of centrifugal fan as claimed in  claim 19 , wherein the first air outgoing angle is larger than or equal to the second air outgoing angle. 
     
     
         22 . The fan impeller structure of centrifugal fan as claimed in  claim 19 , wherein the first air incoming angle is smaller than or equal to the second air incoming angle. 
     
     
         23 . The fan impeller structure of centrifugal fan as claimed in  claim 19 , wherein the first air outgoing angle is smaller than or equal to the second air outgoing angle. 
     
     
         24 . The fan impeller structure of centrifugal fan as claimed in  claim 18 , wherein the second end has a height larger than that of the fourth end. 
     
     
         25 . The fan impeller structure of centrifugal fan as claimed in  claim 18 , wherein the fourth end has a height larger than that of the second end. 
     
     
         26 . The fan impeller structure of centrifugal fan as claimed in  claim 17 , wherein the first blade body has a length larger than that of the second blade body. 
     
     
         27 . The fan impeller structure of centrifugal fan as claimed in  claim 17 , wherein the second blade body has a length larger than that of the first blade body. 
     
     
         28 . The fan impeller structure of centrifugal fan as claimed in  claim 18 , wherein the first end is aligned with the third end. 
     
     
         29 . The fan impeller structure of centrifugal fan as claimed in  claim 19 , wherein the first end is not aligned with the third end and the first and second air inlets are not aligned with each other. 
     
     
         30 . The fan impeller structure of centrifugal fan as claimed in  claim 17 , wherein the number of the first blade bodies is more than the number of the second blade bodies. 
     
     
         31 . The fan impeller structure of centrifugal fan as claimed in  claim 17 , wherein the number of the second blade bodies is more than the number of the first blade bodies.