1994 Volume 60 Issue 578 Pages 3245-3251
The electromagnetic noise of an induction motor is very offensive to human ear. Most offensive electromagnetic noise is generated when natural frequencies of a stator core coincide with or are close to frequencies of the magneto motive forces. Therefore, in order to avoid such noise, it is necessary to estimate natural frequencies of the stator core in the design stage. In this paper, the effects of coil ends on frequencies and modes in the free vibration of the stator core are examined. It was clarified that each coil end does not vibrate as an additional mass, and constitutes an independent vibration system and produces free vibration coupling with the stator core. Based on these results, the authors provide a coupling vibration model with two degrees of freedom which consists of a double ring (stator core and coil end) connected by a spring. Each ring has one degree of freedom. Calculation of this vibration model yields natural frequencies of the stator which are similar to experimental values.
Transactions of the Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers Series A
Transactions of the Japan Society of Mechanical Engineers Series B
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A
