Experimental study of the cooling of a closed type electric motor

The present study aimed at the optimization of the external surface of an i nduction motor of closed type and is carried out experimentaly by consideri ng, in parallel, the thermal aspects and flow distribution around the motor casing. Three non intrusive methods of investigation are used: determinati on of wall temperature fields by infrared thermography, flow visualization by laser sheet and measurement of velocity distribution by laser Doppler an emometry. The results obtained on an already commercialized motor display i mportant overheating of several zones at the casing surface, and have led t o the design of a new configuration of motor casing. The study of a prototy pe motor, equipped with the modified casing, shows a significant improvemen t of the casing irrigation, and consequently an appreciable decrease in sur face temperatures. (C) 2000 Elsevier Science Ltd. All rights reserved.