| 摘要 |
<p>A power transmission fluid composition which has, on a weight basis, an oil-soluble boron content of 0.001 to 0.1%, an oil-soluble phosphorus content of 0.005 to 0.2% and an oil-soluble metal content as metal-containing additive of no more than about 100 ppm and which comprises the following components: a) at least about 70 wt% based on the total weight of the composition of an hydrogenated poly- alpha -olefin oligomer fluid having a kinematic viscosity of 2x10<-6> to 6x10<-6> m<2>/s (2 to 6 cSt) at 100 DEG C; b) on an active ingredient basis, 2 to 20 wt% based on the total weight of the composition of an acrylic viscosity index improver which is in the form of a solution with an inert solvent; c) 4 to 25 wt% based on the total weight of the composition of an oil-soluble dialkyl ester of a C4 to C14 alpha , omega -dicarboxylic acid having a pour point of -45 DEG C or lower; d) a dispersant amount of an oil-soluble ashless dispersant; e) a friction modifying amount an oil-soluble friction modifier; and f) an oil-soluble inhibitor selected from foam inhibitors, copper corrosion inhibitors, rust inhibitors and oxidation inhibitors; with the proviso that the power transmission fluid composition has (i) a kinematic viscosity of at least 6.8x10<-6> m<2>/s (6.8 cSt) at 100 DEG C, (ii) a Brookfield viscosity of 15 Pas (15,000 cP) or less at -40 DEG C, (iii) a kinematic viscosity at 100 DEG C of at least 6.0x10<-6> m<2>/s (6.0 cSt) after 4 hours in the Volkswagen taper roller bearing shear stability test, and (iv) a kinematic viscosity at 100 DEG C of at least 5.0x10<-6> m<2>/s (5.0 cSt) after 20 hours in the Volkswagen taper roller bearing shear stability test.</p> |
