Vibration with ultrasonic frequency could levitate object

with this levitation to support shaft which we call it ultrasonic bearing. This paper give one bidirectional ultrasonic bearing which levitate and support the shaft in lengthways and radial direction

analyse the formation methods of ultrasonic radiation pressure on this kind of bearing

design the structure of the bearing which support the shaft in two directions

and test the max rotate speed of the shaft base on different clearances. Result show that the max rotate speed could be 8946rpm

the higher the rotate speed is

the bigger the centrifugal force is

which will result in the shaft hit the bearing and make the levitation and support function out of work

so it is very important to balance the rotor for improving the function of bidirectional support ultrasonic bearing.