Patent ID: 8851758

Claim:
A bearing device comprising: an outer ring that has a raceway surface on an inner circumferential surface of the outer ring; an inner ring that has a raceway surface on an outer circumferential surface of the inner ring; a plurality of rolling elements that are arranged between the raceway surface of the outer ring and the raceway surface of the inner ring; a retainer that retains the plurality of rolling elements; and a liquid lubricant supply device that supplies an oil separated from a grease to a space between the inner circumferential surface of the outer ring and the outer circumferential surface of the inner ring, the liquid lubricant supply device including: a liquid lubricant passage that provides fluid communication between the inner circumferential surface of the outer ring and the outer circumferential surface of the inner ring; an ultrasonic generator or ultrasonic vibrator that contacts a non-liquid lubricant that is the grease to vibrate the grease in order to supply the oil separated from the grease to the space between the inner circumferential surface of the outer ring and the outer circumferential surface of the inner ring via the liquid lubricant passage; and a non-liquid lubricant storage portion that stores the non-liquid lubricant, wherein the bearing device further comprises: a temperature sensor that detects a temperature of at least one of the outer ring and the inner ring; and a control device that controls the ultrasonic generator or ultrasonic vibrator based on the temperature detected by the temperature sensor, the control device controls the ultrasonic generator or ultrasonic vibrator so that a vibration duration, frequency, or amplitude of the ultrasonic generator or ultrasonic vibrator when the temperature detected by the temperature sensor is a first temperature differs from a vibration duration, frequency, or amplitude of the ultrasonic generator or ultrasonic vibrator when the temperature detected by the temperature sensor is a second temperature, the second temperature being different from the first temperature, the ultrasonic generator or ultrasonic vibrator is arranged inside the non-liquid lubricant storage portion.