How to Analyze the Special Function of a Rotor from Its External Characteristics

From the structural analysis of the rotor, we can divide the rotor of the motor into wound rotor and squirrel cage rotor. In comparison, due to the special characteristics of the production and manufacture of the wound rotor, its structure and slot changes in the degree of freedom is relatively small, we do not specialize in this paper. In this paper, we focus on the relationship between the appearance of the squirrel cage rotor and the performance of the motor.

Open slot rotor and closed slot rotor. With the continuous implementation of environmental protection requirements for the motor, many motor manufacturers will be the original open slot cast aluminum rotor are adjusted to closed slot rotor, compared to the rotor stacking process quality visibility in the reduction of the need for more stringent technology to ensure. Closed slot rotor can eliminate tooth harmonics, effectively improve the electromagnetic vibration of the motor and noise problems; but the degree of closed slot sealing is very delicate, otherwise it will lead to the overall performance of the motor level is low.

Straight and slotted rotors. Non-essential cases do not use the slant slot, both from the motor manufacturing process control and overall performance indicators. However, in order to tend to eliminate the existence of adverse effects of the motor, such as electromagnetic noise of the motor, will be used to rotor slot torsion oblique measures to effectively reduce the impact of motor noise.

Deep slot rotor and double cage rotor. This type of rotor from the outer surface of the rotor can not be seen, the measure is mainly used to solve the starting problem of industrial frequency motor, that is, through the skin effect of the current, increase the resistance of the rotor in the process of motor starting, so as to reduce the starting current of the motor, and the same effect as the winding rotor series resistance starting.

Herringbone slot rotor. This type of rotor for the open slot, you can clearly see the distribution of the rotor guide strip, that is, the rotor axial center to the ends of the dispersion, to achieve the rotor in both directions of the torsion of the slope, the rotor in addition to the special features of the slotted rotor, but also effectively eliminated because of slotted axial force. But for the closed slot herringbone rotor, the appearance is not too obvious, but the rotor turning can be completed after the hidden traces of the large herringbone slot rotor, in the axial center of the rotor there is a clear short-circuit ring, but also the specific embodiment of the aluminum casting process of different manufacturers.