The special motor of compressor is different from the general motor, it runs in a closed environment, and the ambient temperature is 40 ≤ 50 ℃, with the load usage coefficient (for example, the load usage coefficient is 1.25 times). In order to meet the good operation performance of the motor and to reasonably control the increase of production cost, in addition to adopting better electromagnetic design, the temperature rise of the motor can also be properly reduced by improving the ventilation of the motor.

On the premise of keeping the ventilation volume of the motor fan unchanged, reducing the outer diameter of the fan blade and properly increasing the width or number of the fan blade can effectively reduce the mechanical loss and thus improve the efficiency of the motor. On the contrary, in order to meet the performance of the motor, the ventilation volume of the fan can also be increased under the condition that the efficiency has a certain margin. According to experience, compared with increasing the outer diameter of the blade, the fan loss increases with the increase of the blade width and the same ventilation volume. By increasing the ventilation volume of the fan, the temperature rise of the motor and the temperature of the front bearing can be obviously reduced.