US 12,421,471 B2
Low viscosity lubricating fluid for an electric motor system
Susie Hurley, London (GB)
Assigned to Afton Chemical Corporation
Filed by Afton Chemical Corporation, Richmond, VA (US)
Filed on Jun. 7, 2024, as Appl. No. 18/736,805.
Application 18/736,805 is a continuation of application No. 18/342,010, filed on Jun. 27, 2023, granted, now 12,043,817.
Prior Publication US 2025/0002806 A1, Jan. 2, 2025
This patent is subject to a terminal disclaimer.
Int. Cl. C10M 169/04 (2006.01); C10M 135/36 (2006.01); C10M 137/08 (2006.01); C10M 137/10 (2006.01); C10M 141/10 (2006.01); C10M 155/00 (2006.01); C10M 161/00 (2006.01); C10M 177/00 (2006.01); C10N 20/02 (2006.01); C10N 20/04 (2006.01); C10N 30/02 (2006.01); C10N 30/04 (2006.01); C10N 30/06 (2006.01); C10N 40/00 (2006.01); C10N 70/00 (2006.01)
CPC C10M 169/044 (2013.01) [C10M 135/36 (2013.01); C10M 137/08 (2013.01); C10M 137/105 (2013.01); C10M 141/10 (2013.01); C10M 155/00 (2013.01); C10M 161/00 (2013.01); C10M 177/00 (2013.01); C10M 2203/003 (2013.01); C10M 2219/044 (2013.01); C10M 2219/106 (2013.01); C10M 2223/043 (2013.01); C10M 2223/047 (2013.01); C10M 2229/00 (2013.01); C10N 2020/02 (2013.01); C10N 2020/04 (2013.01); C10N 2030/02 (2013.01); C10N 2030/04 (2013.01); C10N 2030/06 (2013.01); C10N 2040/40 (2020.05); C10N 2070/02 (2020.05)] 27 Claims
 
1. An electric motor lubricating fluid suitable for electric or hybrid-electric vehicles, the electric motor lubricating fluid comprising:
one or more base oils of lubricating viscosity;
about 2 to about 4 weight percent of a succinimide dispersant derived from a high-molecular weight polyisobutylene having a number average molecular weight of about 2,000 or greater;
an amine salt of a phosphoric acid ester providing about 40 to about 70 ppm of phosphorus to the electric motor lubricating fluid;
an oil-soluble phosphorus antiwear additive including an ashless dialkyl dithiophosphate providing about 40 to about 70 ppm of phosphorus to the electric motor lubricating fluid;
a sulfur-providing additive including a thiadiazole or derivative thereof providing up to 950 ppm of sulfur to the electric motor lubricating fluid; and
wherein the electric motor lubricating fluid has a kV 100° C. of about 4.5 cSt or less and, about 150 to about 250 ppm of total phosphorus.