Roller bearing

Abstract

Enhanced fretting resistance, high-speed capability, and service live are achieved by a roller bearing comprised of a plurality of rolling elements held between inner and outer races with a cage interposed therebetween, and wherein oil film of lubricating oil of which the dynamic viscosity at 40° C. is 20 to 150 mm 2 /s, and which preferably contains an extreme pressure agent and a corrosion preventing agent, is formed on the raceway surfaces of the inner and outer races, the cage and the rolling elements and grease is enclosed.

1 . A fretting resisting spindle support roller bearing of a low-torque spindle drive, comprising a plurality of rolling elements held between inner and outer races with a cage interposed therebetween, wherein an oil film of lubricating oil of which a dynamic viscosity at 40° C. is at least 120 and not exceeding 150 mm 2 /s and effective to improve fretting resisting properties, and which contains an extreme pressure agent and a corrosion preventing agent, is formed on raceway surfaces of the inner and outer races, said cage and said rolling elements, and wherein a grease is enclosed.  
     
     
         2 . A fretting resisting roller bearing according to  claim 1 , wherein said inner and outer races are made of steel and said rolling elements are made of ceramics.  
     
     
         3 . A fretting resisting roller bearing according to  claim 1 , wherein said inner and outer races are made of steel and said rolling elements are made of an alloy of greater hardness than said inner and outer races.  
     
     
         4 . A fretting resisting roller bearing according to  claim 2 , wherein said rolling elements have a Vickers hardness of at least 1300.  
     
     
         5 . A fretting resisting roller according to  claim 4 , wherein said extreme pressure agent is an organic metallic salt.  
     
     
         6 . A fretting resisting roller bearing according to  claim 5 , wherein said organic metallic salt is selected from the group consisting of molybdenum thiocarbamate, molybdenum dithio phosphate, zinc thiocarbamate, and zinc dithiophosphate.  
     
     
         7 . A fretting resisting roller bearing according to  claim 4 , wherein said corrosion preventing agent is selected from the group consisting of phosphoric acid ester and phosphorous acid ester.  
     
     
         8 . A fretting resisting roller bearing according to  claim 4 , wherein said corrosion preventing agent is molybdenum dithiocarbamate.  
     
     
         9 . A fretting resisting roller bearing according to  claim 3 , wherein said rolling elements have a Vickers hardness of at least 1300.  
     
     
         10 . A fretting resisting roller bearing according to  claim 9 , wherein said extreme pressure agent is an organic metallic salt.  
     
     
         11 . A fretting resisting roller bearing according to  claim 10 , wherein said organic metallic salt is selected from the group consisting of molybdenum thiocarbamate, molybdenum dithiophosphate, zinc thiocarbamate, and zinc dithiophosphate.  
     
     
         12 . A fretting resisting roller bearing according to  claim 1 , wherein said extreme pressure agent is an organic metallic salt.  
     
     
         13 . A fretting resisting roller bearing according to  claim 12 , wherein said organic metallic salt is selected from the group consisting of molybdenum thiocarbamate, molybdenum dithio phosphate, zinc thiocarbamate, and zinc dithiophosphate.  
     
     
         14 . A fretting resisting roller bearing according to  claim 1 , wherein said corrosion preventing agent is selected from the group consisting of phosphoric acid ester and phosphorous acid ester.  
     
     
         15 . A fretting resisting roller bearing according to  claim 1 , wherein said corrosion preventing agent is molybdenum dithiocarbamate.