3 phase electric ac motor noise includes electromagnetic noise, mechanical noise and ventilation noise, the noise of a motor is basically a combination of a variety of noise, to achieve the low noise requirements of the motor, should be a comprehensive analysis of the factors affecting the noise and take measures.
Parts processing precision control is a more effective measure, but there must be good equipment and technology to ensure that such measures can ensure the overall matching effect of motor parts; In addition, the mechanical noise of the motor can be effectively reduced by adopting low noise bearings; By adjusting the groove of stator and rotor and adjusting the slope of rotor groove, the electromagnetic noise of motor can be effectively reduced. The other is the adjustment measures of the motor wind path, many motor manufacturers take measures on the fan and wind hood of the motor to reasonably control the relationship between the motor noise, temperature rise and efficiency. Objectively speaking, the development needs of motor products continue to put forward new topics to motor producers.
The suppression of electromagnetic noise can be done in many ways. For 3 phase asynchronous motors, first of all, the appropriate number of stator and rotor slots must be selected. Generally speaking, the number of slots in the rotor and the number of slots in the stator is relatively different, that is, when the so-called far slot is matched, the electromagnetic noise is small. For the slotted motor, the slotted motor can make the radial force phase shift along the axis of the motor, so the axial mean radial force is reduced and the noise is reduced. If the double chute structure is used, the noise reduction effect is better. The double chute structure divides the rotor into two sections along the axis. The skew direction of each slot is opposite. An intermediate ring is also arranged between the two segments.
In order to reduce the harmonic flux potential, double-layer short moment winding can be used. And avoid using fractional slot winding group. Sinusoidal winding should be used in single-phase motor. In order to reduce the electromagnetic noise caused by the tooth groove, the magnetic groove wedge can be used or the width of the fixed and rotor groove can be reduced until the closed groove is used. When the three-phase motor is running, the voltage should be maintained as symmetrical as possible, and the single-phase motor should run in a rotating magnetic field close to the circle. In addition, during the motor manufacturing process, the ellipticity of the inner circle of the stator and the outer circle of the rotor should be reduced and the rotor should be fixed and concentric, so that the air gap is uniform. Noise can be reduced by reducing the air gap flux density and using a larger air gap. In order to avoid the electromagnetic force and the natural frequency resonance of the housing, an appropriate elastic structure can be used.
Post time: Sep-18-2024
