3. Thermal behavior of a closed machine

The second machine whose thermal behavior is analyzed is also an asynchronous motor, but totally enclosed. Only the outer casing of this motor is actively cooled by air supplied by a fan attached to the shaft. In this case, and in the absence of an internal cooling loop, the classification of the various components making up this system seems much easier than previously. Most stator dissipation is evacuated by the housing via the stack, and rotor dissipation is evacuated via the air gap and stator.

However, an assessment of the main temperature gradients experienced by this type of motor, together with a precise calculation of the loss evacuation paths, will enable us to refine an initial analysis of thermal behavior. A nodal thermal model has been developed, validated