GREASE COMPOSITION FOR PIVOT ASSEMBLY BEARING AND BEARING FOR PIVOT ASSEMBLY CONTAINING THE COMPOSITION SEALED THEREIN

摘要

PROBLEM TO BE SOLVED: To provide a grease composition for pivot assembly bearing, effective for lowering the low-temperature characteristics and flow point without addition of organic lead compound, and having low torque and excellent outgas characteristics and grease-scattering characteristics, and provide a bearing for pivot assembly containing the composition sealed in the bearing. SOLUTION: The grease composition for a pivot assembly bearing is produced by compounding 5-25 mass% thickener and 95-75 mass% base oil with respect to the total mass of the thickener and the base oil. Two or more urea compounds including diurea compounds having an aliphatic, alicyclic and/or aromatic substituents are used as the thickener. A poly-α-olefin mixture having a kinematic viscosity of 40-70 mm2/s at 40°C and prepared by mixing a poly-α-olefin having high viscosity with a poly-α-olefin having a low viscosity in a mass ratio of 15:85 to 30:70 is used as a base oil, and a lead-free additive is used as an additive. The invention further relates to a bearing for pivot assembly containing the grease composition sealed in the bearing. COPYRIGHT: (C)2007,JPO&INPIT