Method for manufacturing fan rotor

Abstract

An exemplary method for manufacturing a fan rotor includes the following steps. First, a discoid-shaped metal sheet is provided. Second, the metal sheet is stamped such that the stamped metal sheet includes a hub at a middle thereof, a blade-portion spaced from and surrounding the hub, and supporting bars interconnecting the hub and the blade-portion. The blade-portion includes outer peripheral blades adjacent to each other. Third, a free end of each blade is curled up by force applied along a direction substantially perpendicular to a plane of the blade-portion. Finally, each blade is bent downward about an axis coinciding with a portion of one side of the blade that connects with an inner periphery of the blade-portion.

What is claimed is: 
     
         1 . A method for manufacturing a fan rotor, comprising:
 providing a metal sheet;   stamping the metal sheet, the stamped metal sheet comprising a hub at a middle thereof, a blade-portion spaced from and surrounding the hub, and a plurality of supporting bars interconnecting the hub and the blade-portion, an outer periphery of the blade-portion comprising a plurality of uniform blades arranged adjacently, the blades being coplanar with each other, each of the blades comprising a first long side, a second long side opposite to the first long side, a first short side, and a second short side opposite to the first short side, the first short side of each blade located near the hub, the second short side of each blade located remote from the hub, the first short side of a given one of the blades dividing the second long side of an adjacent one of the blades into a first portion and a second portion, the first portion located near the hub, the second portion located remote from the hub, and the first long side, the first short side, the second short side and the second portion of the second long side of each blade all having discrete edges;   curling each blade upward by applying upward force to a free end of the blade; and   bending each blade downward about an axis coinciding with the first portion of the second long side.   
     
     
         2 . The method of  claim 1 , wherein the blade-portion is annular, an inner diameter of the blade-portion is defined as r, a shortest distance between the center of the hub and an extension line of the first long side of each blade is constant, the shortest distance is defined as d, and the values of d and r meet the following relationship: 0<d<r. 
     
     
         3 . The method of  claim 1 , wherein a total angle of bending each blade relative to the first portion of the second long side is 90 degrees. 
     
     
         4 . The method of  claim 1 , wherein the metal sheet is malleable. 
     
     
         5 . The method of  claim 1 , wherein upon stamping the metal sheet an outer end of each blade is located more counterclockwise than an inner end of the blade. 
     
     
         6 . A method for manufacturing a fan rotor, comprising:
 providing a metal sheet;   stamping the metal sheet, the stamped metal sheet comprising a hub at a middle thereof, a blade-portion spaced from and surrounding the hub, and a plurality of supporting bars interconnecting the hub and the blade-portion, an outer periphery of the blade-portion comprising a plurality of uniform blades arranged adjacently, the blades being coplanar with each other, each of the blades comprising a first long side, a second long side opposite to the first long side, and a short side interconnecting the first long side and the second long side, the short side of each blade located remote from the hub, the first long side, the short side and the second long side of each blade all having discrete edges;   curling each blade upward by applying upward force to a free end of the blade; and   twisting and stretching each blade at an inner end of the blade such that the short side of the blade is substantially perpendicular to a plane of the blade-portion.   
     
     
         7 . The method of  claim 6 , wherein the blade-portion is annular, an inner diameter of the blade-portion is defined as r, a shortest distance between the center of the hub and an extension line of the first long side of each blade is constant, the shortest distance is defined as d, and the values of d and r meet the following relationship: 0<d<r. 
     
     
         8 . The method of  claim 6 , wherein a total maximum angle of the twisting of each blade is 90 degrees. 
     
     
         9 . The method of  claim 6 , wherein the metal sheet is malleable. 
     
     
         10 . The method of  claim 6 , wherein upon stamping the metal sheet an outer end of each blade is located more counterclockwise than an inner end of the blade. 
     
     
         11 . A method for manufacturing a fan rotor, comprising:
 providing a metal sheet;   stamping the metal sheet, the stamped metal sheet comprising a hub at a middle thereof, a blade-portion spaced from and surrounding the hub, and a plurality of supporting bars interconnecting the hub and the blade-portion, an outer periphery of the blade-portion comprising a plurality of uniform blades arranged adjacently, the blades being coplanar with each other, each of the blades comprising a first long side, a second long side opposite to the first long side, and a short side interconnecting the first long side and the second long side, the short side of each blade located remote from the hub, the first long side, the short side and the second long side of each blade all having discrete edges;   curling each blade upward by applying upward force to a free end of the blade; and   twisting and stretching each blade at an inner end of the blade such that the short side of the blade is substantially perpendicular to a plane of the blade-portion and crosses the plane of the blade-portion.   
     
     
         12 . The method of  claim 11 , wherein the blade-portion is annular, an inner diameter of the blade-portion is defined as r, a shortest distance between the center of the hub and an extension line of the first long side of each blade is constant, the shortest distance is defined as d, and the values of d and r meet the following relationship: 0<d<r. 
     
     
         13 . The method of  claim 11 , wherein a total maximum angle of the twisting of each blade is 90 degrees. 
     
     
         14 . The method of  claim 11 , wherein the metal sheet is malleable. 
     
     
         15 . The method of  claim 11 , wherein upon stamping the metal sheet an outer end of each blade is located more counterclockwise than an inner end of the blade.