Abstract: A rolling bearing 10 comprises races 11, 12 having a raceway 15, 16 and rolling elements 13 having a rolling contact surface, wherein at least the raceway 15, 16 of the races 11, 12 has a machined surface, and a surface layer 11a, 12a is formed on the machined surface by electrochemically or chemically dissolving the machined surface, whereby contamination is substantially reduced.

Abstract: A wheel drive unit is provided to comprise a bearing unit 3c for wheel drive which is light in weight and low in cost. The components constituting the bearing unit 3c for wheel drive have optimum properties to secure the durability thereof. Of the components constituting the bearing unit 3c for wheel drive, the portions indicated by a diagonal grid harching are quench-hardened with the other portions being not quench-hardened and left as they are, whereby the rolling fatigue life and wear-resistance of the components are improved and cracking is prevented.

Abstract: The rust preventive lubricating oil of the present invention concerns a base oil and a rust-preventive agent in an amount of 2-20% by weight on the basis of the whole rust preventive lubricating oil, wherein the base oil contains an ether oil in an amount of at least 20% by weight on the basis of the whole rust preventive lubricating oil. The rust preventive lubricating oil can be applied to the surface of raceway tracks of inner and outer rings, cages for bearings, as well as to bearings, to prevent development of rust, to inhibit generation of cage sound, and to obtain good lubricity, while retaining good compatibility with a grease to be later charged.