Sintered bearing

Abstract

Provided is a sintered bearing (1) obtained by molding raw material powders containing graphite powder and metal powder in a mold, followed by sintering, in which: the graphite powder to be used includes granulated graphite powder; and a ratio of free graphite in a bearing surface (1a) of the sintered bearing is set to from 25% to 80% in terms of an area ratio. An average grain size of the granulated graphite powder is set to from 60 μm to 500 μm. A blending ratio of the granulated graphite powder in the raw material powders is set to from 3 wt % to 15 wt %.

1 . A sintered bearing, which is obtained by molding raw material powders containing graphite powder and metal powder in a mold, followed by sintering, wherein:
 the graphite powder to be used comprises granulated graphite powder; and   a ratio of free graphite in a bearing surface of the sintered bearing is set to from 25% to 80% in terms of an area ratio;   the free graphite is formed by sintering granulated graphite powder;   the granulated graphite powder is formed by granulating fine powders of flake graphite; and   a blending ratio of the granulated graphite powder in the raw material powders is set to from 3 wt % to 15 wt %.   
     
     
         2 . The sintered bearing according to  claim 1 , wherein an average grain size of the granulated graphite powder is set to from 60 μm to 500 μm. 
     
     
         3 . (canceled) 
     
     
         4 . The sintered bearing according to  claim 1 , wherein an apparent density of the granulated graphite powder is set to 1.0 g/cm 3  or less. 
     
     
         5 . The sintered bearing according to  claim 1 , wherein the sintered bearing is used without being impregnated with lubricating oil. 
     
     
         6 . The sintered bearing according to  claim 1 , wherein the sintered bearing is used with being impregnated with lubricating oil.