A lubricant supply unit that supplies lubricating oil to a raceway groove of an inner ring is fixed to an outer ring. The lubricant supply unit is provided with a first and second radially separated electrodes used to supply electric power from an external power source to the micropump. Each of the first and second radially separated electrodes is fixed to an outer face of a tank that is stationary relative to the micropump so as to be exposed on the outside of the lubricant supply unit. The first radially separated electrode is arranged so as to be apart from the second radially separated electrode.