Abstract: The grease composition for constant velocity joints of the invention is characterized by comprising a lubricating base oil, a thickener, carbon black with a mean particle size of not greater than 500 nm, and an organic molybdenum compound. A grease composition for constant velocity joints according to the invention can achieve a highly satisfactory balance between anti-flaking, anti-seizure and anti-wear without using lead compounds, and can sufficiently maintain these properties with long-term use.

Abstract: An array disk system includes a plurality of disk units respectively having at least one disk for storing data and a head for writing the data on the disk, a control unit supplied with data for controlling write operations in which the data are simultaneously written to the disk units which are coupled to the control unit in parallel, and a non-volatile memory for storing data to be written into a defective block of the disk unit. The control unit writes the data into blocks of the disk units when the disk units are free of defective blocks, and writes the data to be written into the defective block of an arbitrary one of the disk units into the non-volatile memory when the arbitrary disk unit includes the defective block. The control unit also has a function of writing the data related to the defective block and stored in the non-volatile memory into the alternate block of the arbitrary disk unit during a free time of the arbitrary disk unit.