Motor products involve relatively many performances, such as power, efficiency, power factor, vibration, noise and temperature rise. In order to ensure that the performance of the motor meets the requirements, some corresponding measures are often taken. However, while ensuring certain performance levels, other performances may be affected. In order to solve the vibration and noise problems of the motor, especially for the control of electromagnetic noise, skewed slots will be used on the stator or rotor of the motor when necessary.

After the motor rotor adopts skewed slots, the electromagnetic torque and induced electromotive force formed are close to the average value of the same rotor bar evenly distributed within a circumference, which can effectively weaken the harmonic electromotive force generated by the tooth harmonic magnetic field, thereby weakening the additional torque caused by these harmonic magnetic fields, and effectively reducing the electromagnetic vibration and noise of the motor. After the rotor adopts skewed slots, although the fundamental electromotive force induced by the rotor will also be reduced, the generally selected skew degree is much smaller than the pole pitch, so it has little effect on the basic performance of the motor. Therefore, rotor skewed slots are commonly used in small and medium-sized cast aluminum rotor asynchronous motors.

Chute is an effective measure to eliminate tooth harmonics. If the noise is electromagnetic noise, the effect is very significant, but if it is caused by other reasons, the effect is very small. An excessively large chute may also cause the reactance current to increase too much and increase the temperature rise of the motor. However, generally the chute cannot exceed two stator pitches (according to 1 to 1.2 times the stator pitch of the chute). Maximum error estimate), usually does not have much impact on temperature rise. If the chute is too small, the noise reduction effect will not be achieved, and the noise will even be greater, but it will have almost no effect on the temperature rise.

From the perspective of motor processing technology, for cage-type motor rotors, the use of beveled slots does not have much impact on the processing technology and related processing parameters. However, for wound rotor motors, the use of beveled slots will increase the difficulty of wire embedding to varying degrees. Therefore, wound rotors should try not to use beveled slots.