| abstract |
There is provided a grease composition decreasing the load sensitivity to a running torque, maintaining necessary performances for a wheel supporting rolling bearing unit, and maintaining a good lubricated condition for a long time, and, a wheel supporting rolling bearing unit having the grease composition packed therein. The grease composition contains base oil, thickeners, rust inhibitors, and anti-wear agents, the base oil contains mineral oil, synthetic oil or blend oil of the mineral oil and the synthetic oil, a mix ratio (mass ratio) of the mineral oil and the synthetic oil is 0:100 to 20:80, a kinematic viscosity of the base oil at a temperature of 40° C. is 70 to 150 mm 2 /s, and a pour point of the base oil is equal to or lower than −40° C. The wheel supporting rolling bearing unit is packed with this grease composition. |