Traction motor cooling device
60°C additional cooling performance at traction motors
Patent proposal, pending, published 02.04.2017
The reason of extra cooling is the self ventilation put behind the motor, the fan is creating underpressure 10.000 Pa (0,1 bar) by sucking the air through fuses drilled into the entrance area to the motor inside.
Main parts from the side of air inlet: air duct, air filter, silencer, nozzled steel sheet, motor, fan, outlet
Operation: The fan is creating underpressure of 0,1 bar (10% pressure drop), the air flow is dependent on fan speed, the nozzles may be adjustable in air inlet allowance. By the pressure change the temperature of the entered air changes by the formula
p1/p2 = T1/T2
101325 Pa / 0,9.101325 Pa = 303°K (30°C)/T2
1 / 0,9 = 303°K / T2
T2 = 303°K . 0,9 = 272,7°K => difference 30°C or K, approx. T2 = 0°C
If this would be made by a fan in front of the motor, an increase of pressure of 10.000 Pa, would increase the entering temperature by 30°C. The difference between the nozzled pressure dropped motor and the pressurized cooling is 60°C.
Result: The new design is better and more efficient as the old one.