Method for lubricating a continuously variable transmission, and a continuously variable transmission

Patent metadata

Field	Value
Publication number	US-9725672-B2
Application number	US-201013579636-A
Country	US
Kind code	B2
Filing date	Nov 24, 2010
Priority date	Feb 17, 2010
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A lubricating oil composition for a continuously variable transmission contains at a specific content: (A) a mineral oil or PAO having a sulfur content of 0.03 mass % or less and a kinematic viscosity at 100 degrees C. from 1.5 mm 2 /s to 3 mm 2 /s; (B) a mineral oil or PAO having a sulfur content of 0.03 mass % or less and a kinematic viscosity at 100 degrees C. from 5.5 mm 2 /s to 8 mm 2 /s; (C) PAO having a kinematic viscosity at 100 degrees C. from 30 mm 2 /s to 400 mm 2 /s; and (D) a polymethacrylate having a mass average molecular weight of 10000 to 40000, in which the total content of the components (C) and (D) is 19 mass % or more and the lubricating oil composition has a kinematic viscosity at 100 degrees C. from 5.5 mm 2 /s to 6.5 mm 2 /s and a kinematic viscosity at −20 degrees C. of 680 mm 2 /s or less.

First claim

The invention claimed is:

1. A method for lubricating a continuously variable transmission comprising contacting a lubricating oil composition with a continuously variable transmission;
wherein said lubricating oil composition comprises components (A), (B), (C) and (D); wherein:
the component (A) contains 45 to 65 mass % of a mineral oil, a poly-alpha-olefin, or a mixture of a mineral oil and a poly-alpha-olefin, wherein the sulfur content of each of said mineral oil and poly-alpha-olefin does not exceed 0.03% by mass and wherein each of the mineral oil and poly-alpha-olefin has a kinematic viscosity at 100 degrees C. in a range of 1.5 mm 2 /s to 3 mm 2 /s;
the component (B) contains 10 to 20 mass % of a mineral oil or a mixture of a mineral oil and a poly-alpha-olefin, wherein the sulfur content of each of said mineral oil and poly-alpha-olefin does not exceed 0.03% by mass, and wherein each of said mineral oil and poly-alpha-olefin has a kinematic viscosity at 100 degrees C. ranging from 5.5 mm 2 /s to 8 mm 2 /s;
the component (C) contains from 5 to 12 mass % of a poly-alpha-olefin having a kinematic viscosity at 100 degrees C. in a range of 30 mm 2 /s to 400 mm 2 /s; and
the component (D) contains from 8 to 14 mass % of a polymethacrylate having a mass average molecular weight in a range of 10,000 to 40,000;
wherein a total content of the components (C) and (D) in said composition is 19 mass % or more;
wherein the mass % of the components (A), (B), (C) and (D) are based on the total mass of said lubricating oil composition; and
wherein the lubricating oil composition has a kinematic viscosity at 100 degrees C. in a range of 5.5 mm 2 /s to 6.5 mm 2 /s and a kinematic viscosity at −20 degrees C. of 680 mm 2 /s or less.

2. A continuously variable transmission, comprising a lubricating oil composition that comprises components (A), (B), (C) and (D); wherein:
the component (A) contains 45 to 65 mass % of a mineral oil, a poly-alpha-olefin, or a mixture of a mineral oil and a poly-alpha-olefin, wherein the sulfur content of each of said mineral oil and poly-alpha-olefin does not exceed 0.03% by mass and wherein each of the mineral oil and poly-alpha-olefin has a kinematic viscosity at 100 degrees C. in a range of 1.5 mm 2 /s to 3 mm 2 /s;
the component (B) contains 10 to 20 mass % of a mineral oil or a mixture of a mineral oil and a poly-alpha-olefin, wherein the sulfur content of each of said mineral oil and poly-alpha-olefin does not exceed 0.03% by mass, and wherein each of said mineral oil and poly-alpha-olefin has a kinematic viscosity at 100 degrees C. ranging from 5.5 mm 2 /s to 8 mm 2 /s;
the component (C) contains from 5 to 12 mass % of a poly-alpha-olefin having a kinematic viscosity at 100 degrees C. in a range of 30 mm 2 /s to 400 mm 2 /s; and
the component (D) contains from 8 to 14 mass % of a polymethacrylate having a mass average molecular weight in a range of 10,000 to 40,000;
wherein a total content of the components (C) and (D) in said composition is 19 mass % or more;
wherein the mass % of the components (A), (B), (C) and (D) are based on the total mass of said lubricating oil composition; and
wherein the lubricating oil composition has a kinematic viscosity at 100 degrees C. in a range of 5.5 mm 2 /s to 6.5 mm 2 /s and a kinematic viscosity at −20 degrees C. of 680 mm 2 /s or less.

Assignees

• Fujita Hiroshi
• Ichihashi Toshihiko
• Kojima Kenji
• Arakawa Yoshie
• Maeda Makoto
• Usuki Hideki
• Idemitsu Kosan Co
• Jatco Ltd
• Nissan Motor

Inventors

• Fujita Hiroshi
• Ichihashi Toshihiko
• Kojima Kenji
• Arakawa Yoshie
• Maeda Makoto
• Usuki Hideki

Classifications

• C10N2040/045

  for continuous variable transmission [CVT] · CPC title

• C10N2020/02

  Viscosity; Viscosity index · CPC title

• C10N2030/06

  Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure · CPC title

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C10N2020/04

  Molecular weight; Molecular weight distribution · CPC title