Device and method for ultrasonic detecting of rotating member based on magnetic fluid coupling

A device for ultrasonic detecting a rotating member based on magnetic fluid coupling, comprising:

• an ultrasonic probe, magnetic field protection rings, a magnetic fluid and a magnetic fluid protection cover;
• the ultrasonic probe is arranged above the rotating member under detection which is horizontally placed, and front ends of a transmitting ultrasonic transducer and a receiving ultrasonic transducer of the ultrasonic probe are provided with the magnetic field protection rings for generating magnetic fields in the magnetic field protection rings;
• and
• the magnetic fluid protective cover is sleeved on a circumferential outer side of the rotating member under detection where a detected position is located, and the front ends of the ultrasonic probe are arranged to penetrate through the magnetic fluid protective cover, a cavity formed between the magnetic fluid protective cover and the rotating member under detection is filled with the magnetic fluid, and the magnetic fluid is a liquid mixture solution, which at least includes oily or aqueous liquid and suspended ferromagnetic particles.