High-Temperature Points in Enclosed Motor Windings: Heat Dissipation & Ventilation

High-Temperature Points in the Windings of Enclosed Motors: Comparison with Radial and Axial Ventilation Structures

The heat dissipation path of an enclosed motor winding follows a radial outward direction from the core to the frame through direct contact conduction. Therefore, the fit between the motor frame and the core is crucial. During the manufacturing process, it is essential to prevent heat dissipation issues caused by frame deformation or dimensional nonconformance. Additionally, the number of cooling fins and the heat dissipation area of the frame must be optimized to ensure effective heat conduction. Measures such as adding external cooling fans can help lower the surface temperature of the frame and enhance cooling performance.

Compared to the middle section of the winding, both ends are in a non-contact state, requiring indirect heat conduction. As a result, the temperature distribution in this type of motor winding shows a pattern of higher temperatures at both ends and lower temperatures in the middle. In low-voltage, high-power motors, where end-space constraints are particularly tight, proper processing and protection of the winding ends become especially critical. This is particularly true for two-pole motors, where the winding ends are more prone to electrical failures.

When the motor core adopts a laminated segmented structure, the advantage of radial heat conduction ensures that the overall core temperature remains relatively balanced. However, one characteristic of this ventilation structure is that the primary heat dissipation path is radial, leading to a temperature gradient from high inside to low outside. When the motor surface temperature rises, the internal temperature is often significantly higher, which may cause excessive heating of not only the stator windings but also the rotor. In severe cases, excessive rotor heating can lead to discoloration (turning blue), indicating serious thermal damage.