US 11,939,551 B1
Lubricating fluid for an electric motor system
Ramnath Iyer, Glen Allen, VA (US); and Lisa Thalen, Fredericksburg, VA (US)
Assigned to Afton Chemical Corporation, Richmond, VA (US)
Filed by Afton Chemical Corporation, Richmond, VA (US)
Filed on Jun. 27, 2023, as Appl. No. 18/342,202.
Int. Cl. C10M 159/12 (2006.01); C10M 133/06 (2006.01); C10M 135/36 (2006.01); C10N 20/04 (2006.01); C10N 30/02 (2006.01); C10N 40/14 (2006.01); C10N 60/12 (2006.01); C10N 60/14 (2006.01)
CPC C10M 159/126 (2013.01) [C10M 133/06 (2013.01); C10M 135/36 (2013.01); C10M 2215/026 (2013.01); C10M 2215/042 (2013.01); C10M 2219/104 (2013.01); C10M 2225/04 (2013.01); C10N 2020/04 (2013.01); C10N 2030/02 (2013.01); C10N 2040/14 (2013.01); C10N 2060/12 (2013.01); C10N 2060/14 (2013.01)] 24 Claims
 
1. An electric driveline fluid comprising:
one or more base oils of lubricating viscosity;
a succinimide dispersant derived from a polyisobutylene having a number average molecular weight of about 2,000 or greater, wherein the succinimide dispersant has up to about 1 weight percent nitrogen and is post treated with a phosphorus containing compound and a boron containing compound, and wherein the succinimide dispersant delivers about 150 to about 270 ppm of dispersant phosphorus (P) to the electric driveline fluid;
a sulfur-providing additive including a thiadiazole or derivative thereof, wherein the thiadiazole or derivative thereof provides at least about 1000 ppm of thiadiazole sulfur (S) to the electric driveline fluid;
wherein the combined dispersant phosphorus and thiadiazole sulfur (P+S) is at least about 1300 ppm and wherein a weight ratio of the dispersant phosphorus to the thiadiazole sulfur (P/S) is at least about 0.1;
a detergent system providing one or more calcium-containing detergents, and wherein the one or more calcium-containing detergents provide no more than about 200 ppm of calcium;
no more than about 0.4 weight percent of friction modifier; and
wherein the electric driveline fluid has a kV100 viscosity of about 3.2 cSt or more, about 150 to about 270 ppm of total phosphorus, and an electrical conductivity of about 130 nS/M or less as measured by a modified conductivity test pursuant to ASTM D2624-15 using the electric driveline fluid and measured at 20 Hz and at 170° C.