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