Sintered alloy and method of manufacturing the same

Abstract

A sintered alloy that enables the reducing of coefficient of friction and the sealing of pores on a surface thereof and a method of manufacturing the same. A sintered alloy body includes a resin film layer and pores. The pores define a porosity ranging from 2 to 35 volume %, each having an inlet portion and an inside portion, defining a pore inlet diameter and a pore inside diameter respectively. The pore inlet diameter ranges from 10 to 200 μm, and an average ratio of the pore inlet diameter to the pore inside diameter is at least. Solid lubricant is dispersed in the resin film layer. After forming the layer 3 , it is pressed against the sintered alloy body. Thus, the layer enters into the pores to closely contact them, thereby sealing the pores, reducing the coefficient of friction due to the solid lubricant.

What is claimed is:  
     
         1 . A sintered alloy comprising: 
 a sintered alloy body formed by compacting material powders and then sintering the same,    wherein said sintered alloy body has pores providing a porosity 2 to 35 volume %, each pore having an inlet portion having a pore inlet diameter and an inside portion having a pore inside diameter, wherein said pore inlet diameter is from about 10 to about 200 μm, and an average ratio of said pore inlet diameter to said pore inside diameter is at least about 2.0,    wherein said sintered alloy body has a resinfilm layer on at least a portion of a surface thereof.    
     
     
         2 . A sintered alloy according to  claim 1 , wherein said sintered alloy body is a bearing body.  
     
     
         3 . A sintered alloy according to  claim 2 , wherein said bearing body has end faces on axially opposite ends of said bearing body and said resin film layer is located on at least a portion of one of the end faces.  
     
     
         4 . A sintered alloy according to  claim 1 , wherein solid lubricant is dispersed in said resin film layer.  
     
     
         5 . A sintered alloy according to  claim 2 , wherein solid lubricant is dispersed in said resin film layer.  
     
     
         6 . A sintered alloy according to  claim 4 , wherein said solid lubricant makes up 1 to 40 volume % of said resin film layer.  
     
     
         7 . A sintered alloy according to  claim 5 , wherein said solid lubricant makes up 1 to 40 volume % of said resin film layer.  
     
     
         8 . A sintered alloy of  claim 4 , wherein said resin film layer contains an effective amount of solid lubricant.  
     
     
         9 . A sintered alloy of  claim 5 , wherein said resin film layer contains an effective amount of solid lubricant.  
     
     
         10 . A method of manufacturing a sintered alloy comprising: 
 forming a sintered alloy body, having pores therein providing a porosity of about 2 to above 35 volume %, wherein each pore has an inlet portion having a pore inlet of about 0 to about 200 μm, and an inside portion having a pore inside diameter; wherein an average ratio of said pore inlet diameter to said pore inside diameter is at least 2.0, and    forming a resin film layer comprising solid lubricant coating on at least a portion of a surface of the sintered alloy body, using solid lubricant coating.    
     
     
         11 . A method of manufacturing a sintered alloy according to  claim 10 , wherein said sintered alloy body is a bearing body.  
     
     
         12 . A method of manufacturing a sintered alloy according to  claim 11 , wherein said bearing body is formed with end faces an axially opposite ends thereof, and said resin film layer is provided on at least a portion of one of the end faces.  
     
     
         13 . A method of manufacturing a sintered alloy according to  claim 10 , further including the step of pressing said resin film layer against said sintered alloy body after forming the resin film layer.  
     
     
         14 . A method of manufacturing a sintered alloy according to claim  11 , further including the step of pressing said resin film layer against said sintered alloy body after forming the resin film layer.  
     
     
         15 . A method of manufacturing a sintered alloy according to  claim 12 , further including the step of pressing said resin film layer against said sintered alloy body after forming the resin film layer.  
     
     
         16 . A method of manufacturing a sintered alloy according to  claim 13 , wherein said pressing is performed during a sizing process.  
     
     
         17 . A method of manufacturing a sintered alloy according to  claim 14 , wherein said pressing is performed during a sizing process.  
     
     
         18 . A method of manufacturing a sintered alloy according to  claim 15 , wherein said pressing is performed during a sizing process.  
     
     
         19 . A method of manufacturing a sintered alloy according to  claim 10 , wherein said resin film layer is formed by printing said solid lubricant coating.  
     
     
         20 . A method of manufacturing a sintered alloy according to  claim 11 , wherein said resin film layer is formed by printing said solid lubricant coating.  
     
     
         21 . A method of manufacturing a sintered alloy according to  claim 19 , wherein said printing comprises is a screen printing process.  
     
     
         22 . A method of manufacturing a sintered alloy according to  claim 20 , wherein said printing comprises is a screen printing process.