RESEARCH ON NON-CONTACT POWER TRANSFER TECHNOLOGY USING ROTARY ULTRASOUND-ASSISTED MACHINING
Rotary ultrasound-assisted machining is a new type of machining technology that combines traditional machining and ultrasonic machining. Compared with traditional processing, rotary ultrasonic assisted machining has the advantages of small cutting force, low cutting heat, high processing precision and high processing efficiency.
It is widely used in single-crystal silicon, engineering ceramics, hard alloys and other hard and brittle materials and carbon fiber composite materials. The processing has broad application prospects. In the rotary ultrasonic assisted machining process, the tool rotates with the spindle of the machine tool, so the signal generated by the ultrasonic power source cannot be transmitted to the ultrasonic vibration structure through the wired method.
There are two main solutions to this problem: contact and non-contact power transmission technologies. Contact-type power transmission adopts carbon brush-slip ring to realize energy transmission. In this way, the carbon brush wears quickly, heat is generated, and ignition and poor contact are easy to occur, which limits the efficiency and reliability of processing. More foreign use is non-contact power transmission. This transmission method is based on the principle of electromagnetic inductive coupling, free from the inadequacies of contact-type power transmission. This paper mainly studies the non-contact power transmission technology for rotary ultrasonic assisted processing devices. The details are as follows:
An equivalent circuit model for the upper and lower coils and ultrasonic vibration structures of a non-contact power transmission system is established in this model. Based on the above analysis, the different methods of circuit matching for the upper and lower coils were analyzed.
Use ANSYS to carry out finite element simulation of non-contact power transmission structure, analyze its magnetic induction intensity distribution and power transmission efficiency, and design related experiments to verify. Based on the simulation, according to the actual needs of processing, a part of non-contact power transmission structure was designed.
Utilizing a self-developed rotary ultrasonic assisted processing device, the ultrasound machining experiment of the deep hole of the preform of the polarization-maintaining fiber of the Panda type was designed and implemented, and the design of the plan and the optimization of the process were completed. The pre-stressed holes with a depth of 250 mm and a diameter of 8 mm were successfully machined and the surface roughness of the inner bores reached Ra 0.8 μm, demonstrating that the partial contactless power transmission structure can be used for actual processing.
