How to Analyze the Quality of Cast Aluminum Rotors

source：未知   time：2024-09-02 09:06nbsp;  click：

The quality of cast aluminum rotors affects the efficiency, power factor, and starting and running performance of motors. In order to comprehensively improve the quality of rotors, it is necessary not only to analyze the defects of cast aluminum rotors, but also to study the various factors affecting the quality of cast aluminum rotors, so as to propose improvement measures. This article briefly introduces the rotor casting method and analyzes the broken bar problem.

Casting aluminum rotors is a secret project. The quality control of rotors depends on process parameters. In a sense, the performance and quality of cast aluminum rotors focus on the casting of the rotors. Casting aluminum method and rotor quality After the squirrel cage rotor is changed from copper bar to casting method, the stray loss of the motor increases by 2 to 6 times. Different casting methods of the rotors have different stray losses. When pressure cast aluminum rotors are used, the stray loss of the motor is the largest. Although centrifugal cast aluminum and vibration cast aluminum are affected by various factors and are prone to defects, the stray loss of the rotor is small. Further research found that the density of the aluminum cage of the die-cast rotor is about 8% lower than that of the centrifugal cast aluminum rotor, and the average resistivity is 13% higher. This makes the main technical and economic indicators of the asynchronous motor with die-cast rotors worse, the core loss, slip rate, and temperature rise all increase, while the minimum torque and efficiency decrease.

The density of die-cast rotor aluminum decreases and the resistance increases because the gas mixed into the aluminum water during die-casting is densely distributed in the rotor cage bars, end rings, fan blades, etc. in the shape of "pinholes". Also, due to the strong pressure, the cage bars and the iron core are in very close contact (even aluminum conductors are scattered between the iron core laminations), and the transverse current greatly increases the stray loss of the motor. The aluminum water of low-pressure cast aluminum comes from the inside of the crucible, and a relatively "slow" low-pressure pouring is adopted, the exhaust is better, and the quality of the cast aluminum rotor is good. The quality of low-pressure cast aluminum rotors is the best, followed by centrifugal cast aluminum, and the worst is pressure cast aluminum.