Deaeration of a lubricant composition
The present invention concerns the use of at least one polyorganosiloxane to release air from a lubricant composition comprising at least one base oil, when lubricating at least one moving part of an electric or hybrid vehicle.
1. A method to release air from a lubricant composition, the method comprising lubricating at least one moving part in a propulsion system of an electric or hybrid vehicle with the lubricant composition comprising at least one base oil, the method further comprises the use of at least one polyorganosiloxane in the lubricant composition, wherein said at least one moving part is a part rotating at a speed ranging from 1000 to 15000 rpm.
2. The method according to claim 1 , wherein the lubricant composition exhibits an initial variation in air volume in the lubricant composition, measured according to standard NF ISO 12152, lower than 6%.
3. The method according to claim 2 , wherein the lubricant composition exhibits an initial variation in air volume in the lubricant composition, measured according to standard NF ISO 12152, lower than 5%.
4. The method according to claim 1 , wherein said polyorganosiloxane is selected from polydimethylsiloxanes.
5. The method according to claim 1 , wherein the lubricant composition comprises from 0.0005 to 2% by weight of polyorganosiloxane(s), relative to the total weight of the lubricant composition.
6. The method according to claim 5 , wherein the lubricant composition comprises from 0.001 to 1.5% by weight of polyorganosiloxane(s), relative to the total weight of the lubricant composition.
7. The method according to claim 1 , wherein the base oil(s) have kinematic viscosity at 100° C. ranging from 4 to 50 mm 2 /s.
8. The method according to claim 1 , wherein the lubricant composition comprises at least 70% by weight of one or more base oils, relative to the total weight of the lubricant composition.
9. The method according to claim 8 , wherein the lubricant composition comprises 80 to 99% by weight of one or more base oils, relative to the total weight of the lubricant composition.
10. The method according to claim 1 , comprising a step wherein bubbling losses in a lubrication system of the vehicle are reduced.
11. The method according to claim 1 , wherein a lubrication system comprises at least one element selected from the bearings positioned between the rotor and stator of an electric motor and the transmission, of an electric or hybrid vehicle.
12. The method according to claim 1 , comprising a step wherein air is released from the lubricant composition.
13. The method according to claim 1 , wherein the step comprising the use of at least one polyorganosiloxane comprises a step of mixing the at least one polyorganosiloxane with the at least one base oil.
14. The method according to claim 1 , wherein said at least one moving part is a part rotating at a speed ranging from 1300 to 12000 rpm.
15. The method according to claim 1 , wherein said at least one moving part is a part rotating at a speed ranging from 5000 to 15000 rpm.
16. A method for reducing losses through bubbling in a lubrication system of an electric or hybrid vehicle propulsion system, the method comprising contacting a lubricant composition comprising at least one base oil and at least one polyorganosiloxane with at least one moving part of the propulsion system of the electric or hybrid vehicle, wherein said at least one moving part is a part rotating at a speed ranging from 1000 to 15000 rpm.
17. The method according to claim 16 , comprises a step at which loss through bubbling is reduced by at least 10%.
18. The method according to claim 16 , wherein the polyorganosiloxane is selected from polydimethylsiloxanes.
19. The method according to claim 16 , wherein the at least one moving part is a part rotating at a speed ranging from 5000 to 15000 rpm.
20. The method according to claim 16 , wherein a lubrication system comprises at least one element selected from the bearings positioned between the rotor and stator of an electric motor and the transmission, of the electric or hybrid vehicle.