Method of supplying lubricating oil to the bearing device and the bearing

A mounting mechanism for supplying lubricating oil to the bearing, to provide a bearing apparatus which can provide a stable lubricant to the bearing with respect to the temperature change of the lubricating oil. A bearing device 100 includes a fuel supply unit 40 can supply lubricating oil to the annular space formed between the inner ring and the outer ring, for detecting the temperature of lubricating oil stored in the oil supply unit and a sensor 60. Oil supply unit includes a reservoir 63 for storing the lubricating oil, and a piezoelectric element 65 is deformed by application of a voltage, the lubricating oil of the reservoir by reducing the volume of the reservoir with the deformation of the piezoelectric body as well as a possible discharge into the annular space, the pump 61 can be supplemented by sucking lubricating oil in the reservoir by increasing the volume, a control signal to a speed corresponding to the rate of change in volume the temperature of the lubricating oil and a control unit 80 for controlling the output to the piezoelectric element. .The