Sliding bearing oil film thickness online monitoring and fault diagnosis method for phase modifier

The invention discloses a sliding bearing oil film thickness online monitoring and fault diagnosis method for a phase modifier, and belongs to the field of oil film thickness detection, and the method comprises the following steps: an ultrasonic pulse transmitting and receiving device generates a pulse signal, and converts the pulse signal into an ultrasonic signal through an ultrasonic transducer; transmitting an ultrasonic signal into the center of the inner circle of a bearing bush of the sliding bearing of the phase modifier from the lower part of the sliding bearing, and receiving an ultrasonic reflection signal by using an ultrasonic transducer; the received ultrasonic reflection signal is forwarded to an oscilloscope through an ultrasonic pulse transmitting and receiving device for filtering and analog-to-digital conversion, and a digital signal is obtained; and calculating the minimum oil film thickness through the digital signal, comparing the minimum oil film thickness with the expert database to ob