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US 5,858,935 AGranted
Automatic transmission fluids with improved transmission performance
AssigneeExxon Chemical Patents Inc.
InventorsRaymond F. Watts, Manoj Tandon
Life of this patent
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Abstract
Power transmitting fluids, especially automatic transmission fluids, possess improved properties such as antiwear, durability, antioxidation, and shift-time performance by incorporation of high viscosity polyalphaolefins.
Claims21
An automobile transmission of improved performance, in combination with a fluid comprising:
- (a) no less than 50 weight percent of a natural lubricating oil having a kinematic viscosity from 1 to 10 mm.sup.2 /s when measured at 100.degree. C.;
- (b) up to 49 weight percent of a synthetic lubricating oil having a kinematic viscosity from 1 to 10 mm.sup.2 /s when measured at 100.degree. C., and
- (c) from 1 to 25 weight percent of a high viscosity polyalphaolefin having a kinematic viscosity from 40 to 500 mm.sup.2 /s when measured at 100.degree. C.
A method of reducing copper wear in an automatic transmission which comprises filling the automatic transmission with a fluid comprising:
- (a) no less than 50 weight percent of a natural lubricating oil having a kinematic viscosity from 1 to 10 mm.sup.2 /s when measured at 100.degree. C.;
- (b) up to 49 weight percent of a synthetic lubricating oil having a kinematic viscosity from 1 to 10 mm.sup.2 /s when measured at 100.degree. C., and
- (c) from 1 to 25 weight percent of a high viscosity polyalphaolefin having a kinematic viscosity from 40 to 500 mm.sup.2 /s when measured at 100.degree. C.
A power transmitting fluid of improved performance, comprising:
- (a) no less than 50 weight percent of a natural lubricating oil having a kinematic viscosity from 1 to 10 mm.sup.2 /s when measured at 100.degree. C.;
- (b) from 3 to 49 weight percent of a synthetic lubricating oil having a kinematic viscosity from 1 to 10 mm.sup.2 /s when measured at 100.degree. C.;
- and
- (c) from 1 to 25 weight percent of a high viscosity polyalphaolefin having a kinematic viscosity from 40 to 500 mm.sup.2 /s when measured at 100.degree. C.
1 more element
Dependencies are inferred from the claim text.