Fan and fan assembly

Abstract

A fan defines a plurality of fixing holes and includes a plurality of protrusions. The plurality of protrusions is located on sides of the plurality of fixing holes. Each protrusion includes a guiding surface. The plurality of guiding surface extends in the plurality of fixing holes. A fan assembly is also provided.

What is claimed is: 
     
         1 . A fan comprising:
 a plurality of fixing holes;   a plurality of protrusions located on sides of the plurality of fixing holes, each of the plurality of protrusions comprising a guiding surface; and   wherein the plurality of guiding surfaces extends into the plurality of fixing holes.   
     
     
         2 . The fan of  claim 1 , wherein each protrusion is substantially a half ring, and the guiding surface is arc-shaped. 
     
     
         3 . The fan of  claim 2 , wherein the plurality of guiding surfaces curve toward a same direction. 
     
     
         4 . The fan of  claim 2 , further comprising a bottom plane, wherein the plurality of protrusions is substantially located on four corners of the bottom plane, and the plurality of guiding surfaces face to each other. 
     
     
         5 . The fan of  claim 2 , further comprising a bottom plane, wherein the plurality of protrusions is substantially located on four corners of the bottom plane, and arcuate directions of the plurality of guiding surfaces are opposite. 
     
     
         6 . The fan of  claim 1 , wherein each protrusion is a ring, and each guiding surface is substantially circular. 
     
     
         7 . The fan of  claim 1 , wherein each protrusion comprises a chamfer, and the chamfer extends from the guiding surface into an edge of the protrusion. 
     
     
         8 . A fan assembly comprising:
 a fan comprising a plurality of protrusions and defining a plurality of fixing holes; and   a circuit board comprising a plurality of fixing posts;   wherein the plurality of protrusions is located on sides of the plurality of fixing holes, each protrusion comprising a guiding surface, the plurality of guiding surfaces extends into the plurality of fixing holes, and the plurality of fixing posts are slid into the plurality of fixing holes guided by the plurality of guiding surfaces.   
     
     
         9 . The fan assembly of  claim 8 , wherein the circuit board further comprises a component, and the component is located on a central portion of the plurality of fixing posts. 
     
     
         10 . The fan assembly of  claim 8 , wherein each protrusion is substantially a half ring, and the guiding surface is arc-shaped. 
     
     
         11 . The fan assembly of  claim 10 , wherein the plurality of guiding surfaces toward a same direction. 
     
     
         12 . The fan assembly of  claim 10 , further comprising a bottom plane, wherein the plurality of protrusions is substantially located on four corners of the bottom plane, and the plurality of guiding surfaces curve toward a centre of the bottom plane. 
     
     
         13 . The fan assembly of  claim 10 , further comprising a bottom plane, wherein the plurality of protrusions is substantially located on four corners of the bottom plane, and arcuate directions of the plurality of guiding surfaces are opposite. 
     
     
         14 . The fan assembly of  claim 8 , wherein each protrusion is a ring, and each guiding surface is substantially circular. 
     
     
         15 . The fan assembly of  claim 8 , wherein each protrusion comprises a chamfer, and the chamfer extends from the guiding surface into an edge of the protrusion.