Application of wireless electromagnetic resonance technology to rotary transformer used in ultrasonic spindle

In order to develop a new style drill for the factories, the ultrasonic spindle was designed. Rotary transformer was introduced to solve the design problems existing in the specification and structure. However, rotary transformer´s voltage conversion ratio is markedly lower than the inductance ratio, it cannot transmit sufficient electric power to the ultrasonic element. Then, this problem is being solved by using electromagnetism resonance technology in this paper.