Wyznaczanie drgań własnych wirnika w bezszczotkowym silniku prądu stałego z magnesami trwałymi

The Brushless Direct Current Motors with Permanent Magnets are become more and more popular in many uses because of high efficiency, the high ratio between electromagnetic torque to mass of the magnetic circuit and higher reliability. Their uses in high speed applications often for which the particularly important determination of natural frequencies of rotor due to possibility of damage machine. The problem of determination of natural frequencies in article is presented for rotor for BLDC machine. Finite Element Program ANSYS was used to calculate natural frequencies of BLDC machine. In aim of qualification of influence selected parts of rotor (magnets, bearings, end shields) on natural frequencies of rotor numerical calculations were done for different models. Numerical results was compared with experimental results from Hammer test with good agreement.