The Research Of The Direct Drive Torque Motor And Its Controller For Machine's Rotary Table

The performance of the rotary table rotative feed servo is more and more important with the development of modern advanced numerical control machine; the research of rotative servo is meaningful. The direct drive permanent magnet synchronous torque motor used for machine rotary table servo is studied.The characteristic of direct drive permanent magnet ring torque motor is analyzed. According to the requirement of high torque density and low torque ripple, the motor application place, and practical design experience, the initial electromagnetic solution is determined, which adopts outer rotor, multi-pole, magnet surface mounted, fractional-slot nonoverlapping winding, stator-cooled and so on. Considering the structure specialty and the precision requirement of the motor design, the finite element analysis method is directly applied to the electromagnetic analysis and calculation.In the way of increasing torque density of the motor and restraining the torque ripple, the torque performance of the motor is optimized. According to the motor specialty that the slot number and the pole number is proximate, the unequal teeth tips width is presented for optimizing torque density. Due to the property that the minimum common multiple between the slot number and the pole number is larger, the pole skewing is presented, this method can remove the low harmonic component of torque ripple, also keeps the higher winding coefficient. The finite element analysis results prove the nationality and validity of the design method, and these measurements are important to improving the motor servo quality. The electromagnetic parameters are determined after the optimization, and taking the mechanical technique into account the prototype is made. The measured results prove the correctness of design methods.The permanent magnet synchronous motor control system is built with TMS320LF2407A. It uses IR2130 for the IGBT drive, and both the speed and current loop are used for high control precision. The hardware is reasonable, and the system has the self-protection function. The program in DSP realizes the current sample, speed calculation, coordinate transformation and space vector control. The system has the performance of high precision and strong real time, which can make the motor satisfy for the demand of high precision machining.