In MIT three-phase induction motors, the heat dissipation to the outside air is realized through the external surface of the housing that has a forced ventilation, by means of a fan mounted on the motor shaft. This dissipation is dependent on the shape and overall exterior area of the shell, which is generally optimized by the inclusion of fins for convection of the generated heat. The fan used must conform to the needs of each engine and must be able to generate sufficient air flow and also with the aid of the shape of the ventilation cap the air flow should be directed to include the entire outer surface of the carcass.
If the air flow reaches only a small part of the housing surface, the ventilation system will be inefficient. Another important factor to maximize the efficiency of the ventilation system is to ensure that the internal temperature drop is decreased to be as large as possible on the outside, ie between the outer surface of the housing and ambient air. That being said, the difference between the ambient temperature and the external surface of the engine will also be a relevant factor to take into account. buy here skf bearing