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-α-olefin oligomer fluid having a kinematic viscosity of 2x10-6 to 6x10-6 m2/s (2 to 6 cSt) at 100°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 α,ω-dicarboxylic acid having a pour point of -45°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 m2/s (6.8 cSt) at 100°C, (ii) a Brookfield viscosity of 15 Pas (15,000 cP) or less at -40°C, (iii) a kinematic viscosity at 100°C of at least 6.0x10-6 m2/s (6.0 cSt) after 4 hours in the Volkswagen taper roller bearing shear stability test, and (iv) a kinematic viscosity at 100°C of at least 5.0x10-6 m2/s (5.0 cSt) after 20 hours in the Volkswagen taper roller bearing shear stability test.
一种动力传动液组合物,按重量计,其油溶性
硼含量为 0.001 至 0.1%,油溶性
磷含量为 0.005 至 0.2%,作为含
金属添加剂的油溶性
金属含量不超过约 100 ppm,该组合物由以下组分组成:
a) 基于组合物总重量至少约 70 wt%的氢化聚-α-烯烃低聚物流体,其在 100°C 时的运动粘度为 2x10-6 至 6x10-6 m2/s (2 至 6 cSt);
b)
丙烯酸粘度指数改进剂,以活性成分计,占组合物总重量的 2 至 20 wt%,其形式为与惰性溶剂的溶液;
c) 基于组合物总重量的 4 至 25 wt%的 C4 至 C14 α,ω-二
羧酸的油溶性二烷基酯,其倾点为 -45°C 或更低;
d) 一种油溶性无灰分散剂的分散剂量;
e) 油溶性摩擦改进剂的摩擦改进量;以及
f) 油溶性
抑制剂,选自泡沫
抑制剂、
铜腐蚀
抑制剂、
铁锈
抑制剂和氧化
抑制剂;
但动力传动液组合物具有以下特性:(i) 100°C 时的运动粘度至少为 6.8x10-6 m2/s (6.8 cSt);(ii) -40°C 时的 Brookfield 粘度为 15 Pas (15,000 cP) 或以下;(iii) 100°C 时的运动粘度至少为 6.0x10-6 m2/s (6.0 cSt),以及 (iv) 在大众锥形滚子轴承剪切稳定性测试中,经过 20 小时后,100°C 的运动粘度至少为 5.0x10-6 m2/s (5.0 cSt)。