Lubricant compositions for providing anti-shudder performance and elastomeric component compatibility

Abstract

Compositions and methods are disclosed for providing anti-shudder performance in power transmission fluids through the incorporation of a non-dispersant viscosity index improver. Further, the disclosed compositions achieve improved compatibility of an elastomeric component with a lubricating fluid through the incorporation of a non-dispersant viscosity index improver.

1 . A power transmitting fluid for use in a power transmitting device, comprising: 
 (a) a major amount of a base oil; and    (b) a minor amount of an additive composition comprising at least one non-dispersant viscosity index improver,    wherein the power transmitting fluid provides anti-shudder performance to the power transmitting device.    
     
     
         2 . The fluid of  claim 1 , wherein the non-dispersant viscosity index improver comprises a polymethacrylate viscosity index improver.  
     
     
         3 . The fluid of  claim 1 , wherein the non-dispersant viscosity index improver is present in an amount from about 0.01 wt % to about 50 wt % in the additive composition.  
     
     
         4 . The fluid of  claim 3 , wherein the non-dispersant viscosity index improver is present in an amount from about 1 wt % to about 25 wt % in the additive composition.  
     
     
         5 . The fluid of  claim 4 , wherein the non-dispersant viscosity index improver is present in an amount from about 3 wt % to about 15 wt % in the additive composition.  
     
     
         6 . The fluid of  claim 1 , wherein the base oil comprises one or more of a natural lubricating oil, a synthetic lubricating oil, and a mixture thereof.  
     
     
         7 . The fluid of  claim 1 , wherein the fluid is free of a dispersant viscosity index improver.  
     
     
         8 . The fluid of  claim 1 , wherein the fluid is suitable for use in an automatic transmission, a continuously variable transmission, a slipping torque converter, a step automatic transmission, a clutch-to-clutch transmission, and a transmission with a wet starting clutch.  
     
     
         9 . The fluid of  claim 1 , wherein the power transmitting fluid provides improved anti-shudder performance relative to a power transmitting fluid free of at least one non-dispersant viscosity index improver and containing a dispersant viscosity index improver.  
     
     
         10 . An automatic transmission lubricated with the fluid of  claim 1 .  
     
     
         11 . The automatic transmission of  claim 10 , wherein the transmission is a continuously variable transmission.  
     
     
         12 . A lubricating fluid having compatibility with an elastomeric component, comprising: 
 (a) a major amount of a base oil; and    (b) a minor amount of an additive composition having at least one non-dispersant viscosity index improver.    
     
     
         13 . The fluid of  claim 12 , wherein the fluid further promotes swelling of the elastomeric component.  
     
     
         14 . The fluid of  claim 12 , wherein the non-dispersant viscosity index improver comprises a polymethacrylate viscosity index improver.  
     
     
         15 . The fluid of  claim 12 , wherein the non-dispersant viscosity index improver is present in an amount from about 0.01 wt % to about 50 wt % in the additive composition.  
     
     
         16 . The fluid of  claim 15 , wherein the non-dispersant viscosity index improver is present in an amount from about 1 wt % to about 25 wt % in the additive composition.  
     
     
         17 . The fluid of  claim 16 , wherein the non-dispersant viscosity index improver is present in an amount from about 3 wt % to about 15 wt % in the additive composition.  
     
     
         18 . The fluid of  claim 12 , wherein the base oil comprises one or more of a natural lubricating oil, a synthetic lubricating oil, and a mixture thereof.  
     
     
         19 . The seals and/or hoses of  claim 12 , wherein the elastomeric component includes one or more of a seal, a hose, a gasket, and a belt.  
     
     
         20 . The seals and/or hoses of  claim 12 , wherein the elastomeric component is composed of any one of a chlorinated polyethylene, a nitrile rubber, a polyacrylate, a fluoroelastomer, and a silicone.  
     
     
         21 . The fluid of  claim 12 , wherein the fluid is suitable for use in an automatic transmission, a continuously variable transmission (CVT), a slipping torque converter, a step automatic transmission, a clutch-to-clutch transmission, and a transmissions with a wet starting clutch.  
     
     
         22 . The fluid of  claim 12 , wherein the compatibility is improved relative to a fluid free of a non-dispersant viscosity index improver.  
     
     
         23 . The fluid of  claim 12 , wherein the compatibility is improved relative to a fluid free of a non-dispersant viscosity index improver and containing a dispersant viscosity index improver.  
     
     
         24 . The fluid of  claim 12 , wherein the fluid is free of a dispersant viscosity index improver.  
     
     
         25 . The fluid of  claim 12 , wherein the fluid further contains a seal swell agent.  
     
     
         26 . A method of lubricating a power transmission, comprising adding to, and operating in, a power transmission having an elastomeric component a fluid as set forth in  claim 12 .  
     
     
         27 . An automatic transmission lubricated with the fluid of  claim 12 .  
     
     
         28 . The automatic transmission of  claim 27  wherein the transmission is a continuously variable transmission.  
     
     
         29 . A method of improving the anti-shudder capabilities of a power transmission fluid, comprising: 
 lubricating a power transmission with a power transmission fluid comprising:    (a) a major amount of a base oil; and    (b) a minor amount of an additive composition comprising at least one non-dispersant viscosity index improver.    
     
     
         30 . A method of improving the torque performance of a power transmission fluid, comprising: 
 lubricating a power transmission with a power transmission fluid comprising:    (a) a major amount of a base oil; and    (b) a minor amount of an additive composition comprising at least one non-dispersant viscosity index improver.    
     
     
         31 . A method of improving the compatibility of a lubricating fluid with an elastomeric component, said method comprising lubricating an elastomeric component with a fluid comprising: 
 (a) a major amount of a base oil; and    (b) a minor amount of an additive composition comprising at least one non-dispersant viscosity index improver.    
     
     
         32 . The method of  claim 31 , wherein the elastomeric component comprises one or more of a seal, a hose, a gasket, and a belt.  
     
     
         33 . The method of  claim 31 , wherein the elastomeric material is composed of one of a chlorinated polyethylene, a nitrile rubber, a polyacrylate, a silicone, and a fluoroelastomer.  
     
     
         34 . A method of promoting seal swell of an elastomeric seal, comprising lubricating the elastomeric seal with a lubricating fluid comprising: 
 (a) a major amount of a base oil; and    (b) a minor amount of an additive composition comprising at least one non-dispersant viscosity index improver.    
     
     
         35 . A method of making a power transmitting fluid having anti-shudder capabilities, comprising adding to a major amount of a base oil a minor amount of an additive composition having a non-dispersant viscosity index improver.  
     
     
         36 . A method of making a lubricating fluid having improved compatibility with an elasotmeric component, comprising adding to a major amount of a base oil a minor amount of an additive composition having a non-dispersant viscosity index improver.