Lubricating grease composition for receleration gear and electric power steering

Abstract

For lubrication of a reduction gear, at least a Ca sulfonate additive is added to a lubricating grease made by an urea compound as a thickener and a synthetic hydrocarbon oil as a base oil.

1 - 4 . (canceled)  
   
   
       5 . A lubricating grease composition, 
 wherein, for lubrication of a structure comprising a metal member and a resin member, at least a Ca sulfonate additive is added to a lubricating grease made by an urea compound as a thickener and a synthetic hydrocarbon oil as a base oil.    
   
   
       6 . The lubricating grease composition according to  claim 5 , wherein the structure comprising a metal member and a resin member is a speed reducing mechanism comprising a metal member and a resin member.  
   
   
       7 . The lubricating grease composition according to  claim 6 , wherein the speed reducing mechanism is a reduction gear.  
   
   
       8 . The lubricating grease composition according to  claim 7 , wherein the reduction gear comprises a gear made of steel and a gear made of a polyamide synthetic resin.  
   
   
       9 . The lubricating grease composition according to  claim 7 , wherein the reduction gear comprises a worm and a worm wheel.  
   
   
       10 . The lubricating grease composition according to  claim 7 , wherein the reduction gear comprises a worm made of a metal and a worm wheel made of a resin.  
   
   
       11 . The lubricating grease composition according to  claim 7 , wherein the reduction gear comprises a worm made of steel and a worm wheel made of a polyamide synthetic resin.  
   
   
       12 . The lubricating grease composition according to  claim 5 , wherein montan wax is also added to the lubricating grease.  
   
   
       13 . An electric power steering apparatus, 
 wherein, for lubrication of a structure comprising a metal member and a resin member, a lubricating grease composition obtained by adding at least a Ca sulfonate additive to a lubricating grease made by an urea compound as a thickener and a synthetic hydrocarbon oil as a base oil is used.    
   
   
       14 . The electric power steering apparatus according to  claim 13 , wherein the structure comprising a metal member and a resin member is a speed reducing mechanism comprising a metal member and a resin member.  
   
   
       15 . The electric power steering apparatus according to  claim 14 , wherein the speed reducing mechanism is a reduction gear.  
   
   
       16 . The electric power steering apparatus according to  claim 15 , wherein the reduction gear comprises a gear made of steel and a gear made of a polyamide synthetic resin.  
   
   
       17 . The electric power steering apparatus according to  claim 15 , wherein the reduction gear comprises a worm and a worm wheel.  
   
   
       18 . The electric power steering apparatus according to  claim 15 , wherein the reduction gear comprises a worm made of a metal and a worm wheel made of a resin.  
   
   
       19 . The electric power steering apparatus according to  claim 15 , wherein the reduction gear comprises a worm made of steel and a worm wheel made of a polyamide synthetic resin.  
   
   
       20 . The electric power steering apparatus according to  claim 13 , wherein montan wax is also added to the lubricating grease.