Temperature rise is a very important performance indicator of motor products, and what determines the temperature rise level of the motor is the temperature of each part of the motor and the environmental conditions in which it is located.
From a measurement perspective, the temperature measurement of the stator part is relatively direct, while the temperature measurement of the rotor part tends to be indirect. But no matter how it is tested, the relative qualitative relationship between the two temperatures will not change much.
From the analysis of the working principle of the motor, there are basically three heating points in the motor, namely the stator winding, the rotor conductor and the bearing system. If it is a wound rotor, there are also collector rings or carbon brush parts.
From the perspective of heat transfer, the different temperatures of each heating point will inevitably reach a relative temperature balance in each part through heat conduction and radiation, that is, each component exhibits a relatively constant temperature.
For the stator and rotor parts of the motor, the heat of the stator can be directly dissipated outward through the shell. If the rotor temperature is relatively low, the heat of the stator part can also be effectively absorbed. Therefore, the temperature of the stator part and the rotor part may need to be comprehensively evaluated based on the amount of heat generated by the two.
When the stator part of the motor heats up severely but the rotor body heats up less (for example, a permanent magnet motor), the stator heat is dissipated to the surrounding environment on the one hand, and part of it is transferred to other parts in the inner cavity. In a high probability, The temperature of the rotor will not be higher than the stator part; and when the rotor part of the motor is severely heated, from the physical distribution analysis of the two parts, the heat emitted by the rotor must be continuously dissipated through the stator and other parts. In addition, the stator The body is also a heating element, and serves as the main heat dissipation link for rotor heat. While the stator part receives heat, it also dissipates heat through the casing. The rotor temperature has a greater tendency to be higher than the stator temperature.
There is also a limit situation. When both the stator and the rotor are severely heated, neither the stator nor the rotor may be able to withstand high-temperature erosion, resulting in the adverse consequences of winding insulation aging or rotor conductor deformation or liquefaction. If it is a cast aluminum rotor, especially If the aluminum casting process is not good, the rotor will be partially blue or the entire rotor will be blue or even flow aluminum.
Post time: Apr-02-2024