| Abstrakt: |
Magnetic flux leakage from the rotor core bridge must be improved in interior permanent magnet motors to improve their performance. The partial non-magnetization of bridges is effective in reducing magnetic flux leakage. In our previous studies, we proposed a new partial nonmagnetization process for silicon steel, which was used for the rotor core. The portion of the silicon steel sheets that becomes a bridge after pressing can be non-magnetized by melting and mixing Ni-Cr-B alloy powder with the silicon steel sheets using a laser beam and then laminated to produce the rotor core. In this study, the effect of B addition to Ni-Cr alloy powder was widely investigated to optimize the B addition amount. Based on the appearance, solidification defect, and magnetic and mechanical strength properties of the improved portion, the optimal content of B was within the range of 0.5-1.0 mass%. Furthermore, core sheet samples with an improved portion, which had the improved length of 1.0mm and has the composition of Fe-13.9 mass%Cr-15.1 mass%Ni-2.3 mass%Si-0.5 mass%B, were prepared by laser and press processing. A rotor core was fabricated using core sheets and evaluated for its magnetic flux and high-speed rotation for practical use. The prototype rotor core exhibited a 32% higher magnetic force and could rotate at speeds of up to 43,000 rotations. It is expected that the size of interior permanent magnet motors will be reduced due to the increased magnetic force. [ABSTRACT FROM AUTHOR] |
